Quick answer: “Molex MX1.25” is the trade shorthand for the Molex PicoBlade 1.25mm-pitch connector system. It is a single-row, wire-to-board and wire-to-wire connector available in 2 to 15 circuits, with a two-point contact design and a friction lock. It is rated 125V AC (RMS)/DC, with a rated current of 1.0A for AWG #26, #28 and #30 and 0.8A for AWG #32, and Molex also publishes a current derating table showing up to 2.5A at 2 circuits depending on gauge. Operating temperature is −40°C to +105°C, contact resistance is 20mΩ max, insulation resistance is 100MΩ min, and dielectric strength is 250V AC (RMS) for one minute. Mating durability is 30 cycles with gold plating. The KONNRA KR1250 series is documented as the cross-reference equivalent, offered as four wafer types plus a housing and a terminal.
At a glance
| Common trade name | Molex MX1.25 · Molex 1.25mm · “PicoBlade” |
| Official Molex product family | PicoBlade (1.25mm) — distinct from Pico-EZmate 1.20mm |
| Pitch | 1.25mm |
| Configuration | Single row, wire-to-board and wire-to-wire |
| Circuits | 2 to 15 |
| Voltage rating | 125V AC (RMS)/DC |
| Rated current | 1.0A (AWG #26, #28, #30) · 0.8A (AWG #32) |
| Reference derating | Up to 2.5A at 2 circuits (AWG #26), down to 1.0A at 15 circuits |
| Applicable wire | AWG #26 to #32 |
| Insulation O.D. | φ1.0mm max (terminal 50058802*) · φ1.04mm max (terminal 50079802*) |
| Contact resistance | 20mΩ max (5mΩ max for the crimped portion) |
| Insulation resistance | 100MΩ min |
| Dielectric strength | 250V AC (RMS), 1 minute |
| Operating temperature | −40°C to +105°C (including terminal temperature rise) |
| Durability | 30 cycles (gold plating) |
| Contact design | Two-point contact |
| Retention | Friction lock |
| Plating options | Gold flash · 0.38µm min gold · tin |
| Mounting | Through-hole and SMT, vertical and right-angle |
| Assembly feature | Vacuum caps and a flat pick-and-place area on SMT headers |
| Standards | UL File E29179 |
| KONNRA equivalent | KR1250 (wire-to-board) · KR1251 (wire-to-wire) |
Is “Molex MX1.25” the same as PicoBlade?
Yes. Molex does not sell a product called “MX1.25” — the string is trade shorthand built from the 1.25mm pitch, and it maps to the PicoBlade 1.25mm Connector System. Molex’s own series numbers are 51021 for the receptacle housing and 53048 for the right-angle plug assembly.
The distinction that matters is PicoBlade versus Pico-EZmate. These two Molex families are constantly confused because the names are nearly identical and both are used in compact consumer electronics:
| PicoBlade | Pico-EZmate | |
|---|---|---|
| Pitch | 1.25mm | 1.20mm |
| Trade shorthand | “MX1.25” | “MX1.2” |
| Configuration | Wire-to-board and wire-to-wire | Wire-to-board |
| Mating direction | Vertical and right-angle | Vertical |
| Contact design | Two-point contact, friction lock | Friction lock with audible click, polarizing key |
| Rated current | 1.0A (AWG #26–30) | 1.5A |
| Voltage | 125V | 50V |
They are not interchangeable, and 1.25mm is not 1.20mm. A PicoBlade housing will not mate with a Pico-EZmate header. Note the counter-intuitive part: the larger-pitch PicoBlade is rated lower than the smaller-pitch Pico-EZmate — 1.0A versus 1.5A — while carrying a higher voltage rating, 125V versus 50V. Do not assume the bigger connector is the stronger one.
Rule of thumb: on any Molex sub-2mm connector, confirm the pitch on the drawing before cross-referencing. Molex alone runs Pico-EZmate at 1.00mm, 1.20mm and 1.80mm, PicoBlade at 1.25mm, and Pico-Clasp at 1.00mm — and none of them mate.
What Is the Molex PicoBlade 1.25mm Connector?
The PicoBlade is a 1.25mm-pitch, single-row connector system that covers both wire-to-board and wire-to-wire, in 2 to 15 circuits, with through-hole and SMT mounting in vertical and right-angle orientations. It has been a mainstream choice in compact consumer and industrial electronics for long enough that Molex positions it as a de facto standard for space-constrained wiring.
Two design choices define it:
- A two-point contact design. Molex describes this as providing “a reliable electrical connection” in rugged applications subject to shock, vibration or rough handling — the two contact points give redundancy against the terminal being dislodged. This is the PicoBlade’s signature, and it is why the series shows up in applications that would otherwise use a simpler single-point contact.
- A friction lock. Retention comes from friction rather than a positive latch, and Molex pairs it with the two-point contact to keep the mated pair stable under vibration.
Key characteristics:
- 1.25mm pitch, single row, 2 to 15 circuits
- Two-point contact design — redundant contact points for shock and vibration resistance
- Friction lock for secure mating retention
- 125V AC (RMS)/DC rating
- 1.0A rated current at AWG #26, #28 and #30; 0.8A at AWG #32
- Current derating published — Molex gives a reference table by gauge and circuit count, up to 2.5A at 2 circuits
- Gold plating options — flash or 0.38µm minimum, for higher conductivity than tin
- 30-cycle mating durability with gold plating
- Wire-to-board and wire-to-wire in the same family
- Vacuum caps and a flat area on SMT headers for industry-standard pick-and-place nozzles
- UL File E29179
A short glossary, because this series uses specific terms
- Receptacle housing — the wire-side half. Molex’s PicoBlade housing series is 51021.
- Receptacle terminal — the crimp contact. PicoBlade uses four, split by wire gauge and plating thickness.
- Plug assembly / header — the board-mounted half. Molex’s right-angle plug assembly series is 53048.
- Two-point contact — a contact geometry where each mating pair touches at two places, so a single disturbed contact point does not break the circuit.
- Friction lock — retention by friction between the housing and the header, with no separate latch to release.
- Rated current — the current the connector is rated to carry continuously, quoted by Molex per wire gauge.
- Current derating — a lower current limit that applies as more circuits carry current simultaneously and the assembly heats up. Molex publishes this separately from the rating, and marks it as reference data.
- Insulation O.D. — the outside diameter of the wire’s insulation. The crimp barrel must match it.
- Vacuum cap — a flat cap on top of an SMT header sized for a pick-and-place nozzle.
- Hot-mating — mating or unmating a connector while current is flowing. Molex explicitly excludes it on this series.
Molex PicoBlade 1.25mm and KONNRA KR1250 Specifications
| Parameter | Molex PicoBlade 1.25mm (Molex documentation) | KONNRA KR1250 (KONNRA documentation) |
|---|---|---|
| Pitch | 1.25mm | 1.25mm |
| Row configuration | Single row | Single row |
| Connection type | Wire-to-Board and wire-to-wire | Wire-to-Board |
| Circuits | 2 to 15 | 2 to 16 |
| Voltage rating | 125V AC (RMS)/DC | 125V |
| Rated current | 1.0A (AWG #26–30) · 0.8A (AWG #32) | 1A |
| Applicable wire | AWG #26 to #32 | AWG #28 to #32 (per KONNRA’s stated wire range) |
| Insulation O.D. | φ1.0 / 1.04mm max, by terminal | 0.4 to 0.8mm |
| Contact resistance | 20mΩ max (5mΩ max crimped portion) | 20mΩ max |
| Insulation resistance | 100MΩ min. | 100MΩ min. |
| Dielectric withstanding voltage | 250V AC (RMS) / 1 minute | 500V AC / minute |
| Operating temperature | −40°C to +105°C (incl. terminal rise) | −40°C to +105°C |
| Durability | 30 cycles (gold plating) | Not stated |
| Housing material | High heat resistant polyamide | PBT / LCP / PA9T / Phosphor Bronze, UL94 |
| Contact material | — | Phosphor Bronze |
| Plating | Gold flash · 0.38µm min gold · tin | Gold flash / Tin over nickel |
| Contact design | Two-point contact | Two-point contact |
| Lock | Friction lock | Friction lock (bevels engaging the housing’s locking window) |
| Mounting | Through-hole and SMT, vertical and right-angle | DIP and SMT, vertical and right-angle |
| Assembly feature | Vacuum caps and flat pick-and-place area on SMT headers | SMT headers with solder lugs as strain relief |
| Standards | UL File E29179 | RoHS compliant |
| Mates with | PicoBlade housing 51021 / plug assembly 53048 | KR1250 wafer / KR1250 housing |
Where the two documents agree: the pitch, the single-row configuration, the 125V voltage rating, the 20mΩ contact resistance, the 100MΩ insulation resistance, the −40°C to +105°C temperature range, the two-point contact design, and the friction lock. On this series the agreement is broad.
Where they differ: the current rating at AWG #32, the applicable wire range, the insulation diameter window, the dielectric withstanding voltage, the available circuit counts, the durability figure, and the plating options. Each is covered below.
” — ” indicates the parameter is not stated in the manufacturer documentation reviewed for this guide.
Figure 1 — KONNRA KR1250 series: 1.25mm pitch PicoBlade wire-to-board connector
➡️ View the KONNRA KR1250 MX1.25 (PicoBlade) Connector
The Current Rating Is Three Numbers, Not One
The PicoBlade’s current specification is the parameter most often quoted wrong, because Molex publishes it at three different levels and only one of them is the rating.
Level 1 — the rated current, by wire size.
| Wire size | Rated current (MAX.) | Insulation O.D. |
|---|---|---|
| AWG #26 | 1.0A | φ1.0mm max (50058802*) · φ1.04mm max (50079802*) |
| AWG #28 | 1.0A | same |
| AWG #30 | 1.0A | same |
| AWG #32 | 0.8A | same |
Level 2 — the reference derating table, by gauge and circuit count. Molex publishes this separately, and marks it as reference data.
| AWG | 2 circuits | 8 circuits | 15 circuits |
|---|---|---|---|
| 26 | 2.5A | 1.5A | 1.0A |
| 28 | 2.0A | 1.5A | 1.0A |
| 30 | 1.5A | 1.0A | 1.0A |
| 32 | 1.5A | 1.0A | 0.8A |
Molex’s conditions for that table: values are for reference only, deratings are based on not exceeding a 30°C temperature rise, temperature rise is measured in the barrel area of the crimp terminal, the data is for all circuits powered, and — the one that matters most in practice — PCB trace design can greatly affect temperature rise results.
Level 3 — the sum. Molex adds a note: “Do not allow the sum of the current used on several circuits to exceed the maximum allowable current.” The per-circuit figure is not the whole answer.
What this means for a cross-reference. KONNRA documents the KR1250 at a flat 1A. That matches Molex’s rated current for AWG #26, #28 and #30 — but Molex rates AWG #32 at 0.8A, so a KR1250 design running 1A on AWG #32 has no margin against the original specification. If your harness uses #32, treat the applicable figure as 0.8A and confirm it, rather than reading the flat 1A as covering every gauge.
And a warning about the derating table. The 2.5A at 2 circuits is real, and it is also the single most misquoted number on this connector. It is reference data for a 30°C temperature rise with all circuits powered on a specific test board — not a rating, and not independent of your layout. Molex says so explicitly. If your design needs 2.5A through two PicoBlade circuits, the number to work from is your own temperature-rise test on your own board, not a datasheet row.
Two-Point Contact and the Friction Lock
Molex’s stated reason for the two-point contact design is blunt: “rugged applications can be subject to shock, vibration or rough handling that can dislodge the terminals and cause signal interference.” A two-point contact means each mating pair touches in two places, so a single disturbed contact point does not open the circuit. That redundancy is the reason to specify a PicoBlade rather than a simpler single-point connector at a similar pitch, and it is the first thing to preserve when you cross-reference.
The retention side is a friction lock — no positive latch, retention by friction between the housing and the header. KONNRA describes the mechanism in specific terms that align with Molex’s: two locking bevels in the crimp housing engage the locking window of the connector housing, generating the friction that holds the pair together.
But do not size your cable retention from the lock. Molex’s own insertion and withdrawal force table shows how modest the friction is:
| Circuits | Withdrawal force MIN, 1st mating | Withdrawal force MIN, 30th cycle |
|---|---|---|
| 2 | 2.8N (0.28 kgf) | 1.8N (0.18 kgf) |
| 5 | 3.8N (0.38 kgf) | 2.8N (0.28 kgf) |
| 8 | 5.2N (0.53 kgf) | 4.3N (0.43 kgf) |
| 15 | 7.3N (0.74 kgf) | 6.3N (0.64 kgf) |
A 2-circuit connector holds with under 3 newtons, and that falls to under 2 newtons after 30 cycles. The friction lock keeps the pair mated; it does not carry your cable load. Molex’s design guidance says the same thing from the other direction: tie the cable at least 50mm from the connector edge, and apply force evenly across all wires, so the terminals can float freely in their pockets.
Durability Is 30 Cycles
Molex specifies the PicoBlade’s mating durability at 30 cycles with gold plating. That is a low number for a connector that may be opened repeatedly for service, and it is worth stating plainly because it is rarely quoted in summaries.
KONNRA does not publish a cycle count for the KR1250. If your product involves field service, board-level rework, or repeated reconnection during test, ask for the figure — and regardless of the answer, design so that this connector is not the one being cycled. The withdrawal force table above shows retention falling measurably by the 30th cycle, which is the same message from a different direction.
Molex PicoBlade = KONNRA KR1250: Part Number Cross-Reference
| Molex PicoBlade component | Molex part number | KONNRA equivalent |
|---|---|---|
| Receptacle housing | 51021 series (51021**00) |
KR1250 Housing |
| Crimp terminal, AWG #26–28 | 500798020 (gold flash) · 500798025 (0.38µm min gold) |
KR1250 Terminal |
| Crimp terminal, AWG #28–32 | 500588020 (gold flash) · 500588025 (0.38µm min gold) |
KR1250 Terminal |
| Plug assembly, right angle | 53048 series — 53048**60 (gold flash) · 53048**50 (0.38µm min gold) |
KR1250 right-angle wafer |
| Straight / vertical header | PicoBlade vertical header range | KR1250 straight wafer |
| Wire-to-wire variant | PicoBlade wire-to-wire range | KR1251 |
The six orderable components on the KONNRA side, each with its own page:
| Component | KONNRA page |
|---|---|
| DIP Right Angle Wafer | DIP Right Angle Wafer |
| DIP Straight Wafer | DIP Straight Wafer |
| SMT Right Angle Wafer | SMT Right Angle Wafer |
| SMT Straight Wafer | SMT Straight Wafer |
| Housing | KR1250 Housing |
| Terminal | KR1250 Terminal |
Which crimp terminal goes with which wire — and which finish
Molex splits the PicoBlade terminal across four part numbers: two wire ranges, each in two plating thicknesses.
| Terminal | Wire range | Gold thickness | Use it for |
|---|---|---|---|
| 500798020 | AWG #26–28 | flash | Heavier wire, entry-level finish |
| 500798025 | AWG #26–28 | 0.38µm min | Heavier wire, specified gold thickness |
| 500588020 | AWG #28–32 | flash | Lighter wire, entry-level finish |
| 500588025 | AWG #28–32 | 0.38µm min | Lighter wire, specified gold thickness |
The two ranges overlap at AWG #28, and at that gauge the plating spec decides as much as the wire. Both terminal families cover #28, so you have four options and two independent questions — which gauge family, and which finish. Molex makes the distinction explicit: flash versus 0.38µm minimum. That is exactly the specification a BOM line reading simply “gold plated” fails to record, and it is the difference between a mating interface specified to a measurable thickness and one that is not.
Insulation diameter differs by terminal as well: the 50058802* family allows φ1.0mm maximum insulation, and the 50079802* family allows φ1.04mm.
KONNRA documents one terminal with a stated range of AWG #28 to #32, offered as “Gold flash / Tin over Nickel”. Two things follow: the AWG #26 path is not covered by the published KR1250 wire range, and the 0.38µm gold option is not documented. Both are worth raising on the enquiry if your design depends on them.
Figure 2 — KR1250 crimp terminal for the 1.25mm PicoBlade interface
Figure 3 — KR1250 housing
Circuit Counts and the AWG #26 Gap
| Circuits | |
|---|---|
| Molex PicoBlade | 2 to 15 |
| KONNRA KR1250 | 2 to 16 (as documented) |
Molex states the PicoBlade is “available in 2 to 15 circuits, Tin- and Gold-plated versions with through-hole and SMT mounting, and vertical and right-angle orientations”, and the derating and force tables both run to 15 circuits. KONNRA documents the KR1250 as 2 to 16 positions — one position beyond the original range. Confirm the exact count rather than assuming the ranges match.
The wire range gap matters more than the circuit gap. Molex’s PicoBlade covers AWG #26 to #32, and AWG #26 is the gauge that carries the highest derated current in Molex’s own table (2.5A at 2 circuits) and the highest crimp pull-out force (19.6N minimum, against 9.8N at AWG #28). KONNRA’s stated KR1250 wire range is AWG #28 to #32, which does not cover #26.
If your harness uses AWG #26, say so. It is the heaviest wire in the family, it is where the current capability is concentrated, and it is outside the published KR1250 range.
Specification Differences to Verify Before You Cross-Reference
Ten points deserve attention before you sign off an MX1.25 cross-reference.
- Rated current at AWG #32. Molex rates AWG #32 at 0.8A; KONNRA documents a flat 1A. At AWG #26, #28 and #30 the figures match at 1.0A — so this is specifically an AWG #32 issue, and it is 25% optimistic at that gauge.
- The applicable wire range does not reach AWG #26. Molex’s PicoBlade covers AWG #26 to #32. KONNRA’s stated KR1250 wire range is AWG #28 to #32. AWG #26 is the gauge where the family’s current capability and crimp strength are concentrated — 2.5A at 2 circuits in the reference derating table, and a 19.6N minimum crimp pull-out force against 9.8N at AWG #28. If your harness uses #26, raise it explicitly.
- The insulation diameter window is narrower on the KONNRA side. Molex allows φ1.0mm maximum insulation on the
50058802*terminals and φ1.04mm on the50079802*terminals. KONNRA documents 0.4 to 0.8mm. A wire with 0.9mm insulation passes Molex’s specification and falls outside KONNRA’s stated maximum — and the KONNRA figure does publish a lower bound, so check both ends against your cable.
- Dielectric withstanding voltage differs by a factor of two — in KONNRA’s favour. Molex specifies 250V AC (RMS) for one minute. KONNRA documents 500V AC / minute. A higher figure on the replacement is not automatically a problem, but it is a different test claim, so confirm what is being tested and between which points before you rely on it. Note that the rated voltage — 125V — is the same on both sides.
- Mating durability is published by Molex and not by KONNRA. Molex specifies 30 cycles with gold plating. KONNRA publishes no cycle count for the KR1250.
- Plating thickness is specified by Molex and not by KONNRA. Molex offers three finishes — gold flash, 0.38µm minimum gold, and tin — and the thickness is part of the terminal part number, so it is unambiguous at ordering time. KONNRA documents “Gold flash / Tin over Nickel” without a thickness figure. If your qualification names a gold thickness, ask for the micron value.
- The KONNRA page contradicts itself on plating. The specification table states “Gold Flash/Tin over Nickel”, while the advantages text states that “the contact area is tin-plated”. Those describe different finishes on the same mating interface. Resolve which one applies before quoting, because on a two-point contact interface the finish is what determines long-term contact resistance stability.
- Circuit counts: 2 to 15 on the Molex side, 2 to 16 on the KONNRA side. One position beyond the original range. Confirm the count you intend to order.
- Wire-to-board versus wire-to-wire. KONNRA’s KR1250 Overview states that the series supports both wire-to-wire and wire-to-board connections, but KONNRA’s own 1.25mm listing categorises KR1250 as Wire-to-Board, and the wire-to-wire part in the family is KR1251. If your design is wire-to-wire, the cross-reference you want is KR1251, not KR1250.
- Applicable wire construction. Molex specifies that the applicable wire is, in principle, tin-plated copper stranded wire, and that other constructions require consultation and evaluation. KONNRA does not state an applicable wire construction. If you are using anything other than tin-plated copper stranded — silver-plated, solid core, or a high-flex construction — ask before you qualify.
Design Cautions Worth Carrying Into Your Review
Molex publishes an unusually detailed set of usage constraints for this series. They are not marketing, they are the failure modes the product is known to have, and they are the most useful thing in the specification. KONNRA does not publish an equivalent list.
- Do not mate or unmate under load. Molex states the product is not designed for mating and unmating under an active electrical circuit — doing so can cause a spark and product damage. If your service procedure involves disconnecting this connector live, that procedure needs changing.
- Tie the cable at least 50mm from the connector, with the force applied evenly across all wires, so the terminals float freely in their pockets. This is the retention answer for a friction-lock connector.
- A continuous pulling or stress force must not be present when mated — it can damage the contact area or the crimp.
- Withdraw slowly, axially and straightly. Angled or rough withdrawal can damage the connector.
- Use a new housing after extracting a terminal. Extracting a crimp terminal with a jig can deform the housing lance and “reduce the terminal retention force enormously” after re-insertion. Molex’s guidance is to fit a new housing when repairing crimp terminals.
- Mating alignment matters. Mate along the mating axis. If you must mate diagonally, contact the external faces at under 10° and push from there.
- Respect the per-circuit rating, and the sum. Molex states that the sum of the current across several circuits must not exceed the maximum allowable current, on top of the per-circuit figure.
- Do not wash the connectors — Molex states this may damage the product’s function.
- Avoid sympathetic vibration between the wires and the PCB. Molex’s guidance is to fix both wires and PCB to the chassis, because sustained relative movement wears the contact area.
- Expect contact resistance to rise after environmental exposure. Molex specifies 20mΩ max initially, but 40mΩ max after vibration, mechanical shock, temperature cycling, heat, cold, humidity, salt spray, and SO₂ and NH₃ gas exposure. All of those tests are specified with conditions in the datasheet. If your specification quotes a single contact-resistance figure without saying which condition it applies to, it is incomplete.
Components and Configuration Options
The KR1250 is specified as six separately orderable components — four wafer types plus a housing and a terminal — which is what lets the same series serve through-hole and SMT designs in both vertical and right-angle orientations.
Wafer (board-mounted headers)
Four options, covering both mounting technologies and both orientations.
Figure 4 — KR1250 right-angle DIP wafer
Figure 5 — KR1250 straight DIP wafer
Figure 6 — KR1250 right-angle SMT wafer
Figure 7 — KR1250 straight SMT wafer
Two notes on the SMT route. First, KONNRA states that its SMT headers carry solder lugs that act as strain relief as well as securing the connector — which addresses the solder-joint cracking risk that Molex’s own caution list warns about. Second, if you are going through an SMT line, Molex’s PicoBlade SMT headers provide vacuum caps and a flat area for industry-standard pick-and-place nozzles; confirm the equivalent placement feature on the wafer you specify.
Series documentation
- KR1250 series engineering drawing (PDF)
- KR1250 product specification (PDF)
- KR1250 package specification (PDF)
➡️ Request drawings for your orientation and mounting type
What the Molex PicoBlade Is Used For
Molex describes the PicoBlade as “ideal for space-constrained wire-to-wire and wire-to-board applications”, and the series is used across consumer electronics, industrial equipment, medical equipment and commercial vehicles.
| Application | Why the PicoBlade fits |
|---|---|
| Compact consumer electronics and handhelds | 1.25mm pitch in 2 to 15 circuits, with a body sized for tight board layouts |
| Applications subject to shock, vibration or rough handling | The two-point contact design exists specifically to stop terminals being dislodged and causing signal interference |
| Wire-to-board runs that may be re-routed | The friction lock plus the two-point contact give a re-matable pair without a positive latch to break |
| Mixed board-and-harness designs | The family covers wire-to-board and wire-to-wire, so both ends of a run can use the same contact system |
| Boards assembled on an SMT line | SMT headers with vacuum caps and a flat placement area for standard nozzles |
| Medical and industrial equipment | −40°C to +105°C range, UL File E29179, and a qualification route through KONNRA’s ISO13485 and IATF16949 systems |
| Automotive and commercial vehicle interiors | KONNRA positions the 1250 series toward automotive and commercial vehicle use; confirm the automotive-grade variant and its LV214 / US CAR-2 certification if your programme requires it |
| Wire-to-wire inline connections | The same contact system appears on both sides; KONNRA cross-references the wire-to-wire variant as KR1251 |
What it is not for. At a rated 1.0A per circuit — 0.8A on AWG #32 — the PicoBlade is a signal and low-power interface, not a power connector. And it is explicitly not for hot-mating: do not design a service procedure that disconnects this connector under load.
PicoBlade 1.25mm vs Everything Else at 1.25mm — and Below
1.25mm is the most crowded pitch in the connector industry. Three manufacturers, at least six systems, and no two of them mate.
| Connector system | Pitch | Current | Voltage | Wire | KONNRA equivalent |
|---|---|---|---|---|---|
| Molex PicoBlade | 1.25mm | 1.0A (0.8A @ AWG #32) | 125V | AWG #26–32 | KR1250 · KR1251 |
| Molex PanelMate | 1.25mm | 1A | 125V | — | KR1253 |
| Hirose DF13 | 1.25mm | 1A | 150V | — | KR1256 |
| Hirose DF14 | 1.25mm | 1A | 150V | — | KR1255 |
| JST GH | 1.25mm | 1A | 50V AC/DC | AWG #30–26 | KR1259 |
| Molex Pico-EZmate | 1.20mm | 1.5A | 50V | AWG 28–30 | KR1200 |
| JST ACH | 1.2mm | 2A (1–3 ckt) · 1.5A (4–5 ckt) | 50V AC/DC | AWG #32–28 | KR1201 |
| JST SH | 1.00mm | 1A | 50V AC/DC | AWG #32–28 | KR1000 |
” — ” means the figure is not verified from that manufacturer’s own documentation for this guide. The PanelMate, DF13 and DF14 rows are taken from KONNRA’s published series data; their pitch and current figures are consistent with the manufacturers’ own documentation.
Three things this table settles:
- “1.25mm” identifies a pitch, not a connector. Five different systems sit at exactly 1.25mm here, from three manufacturers. KONNRA cross-references them as KR1250/KR1251 (PicoBlade), KR1253 (PanelMate), KR1255 (DF14), KR1256 (DF13) and KR1259 (JST GH). Getting the pitch right is only the first step.
- Going smaller can mean more current, not less. Molex’s own Pico-EZmate at 1.20mm is rated 1.5A, and JST’s ACH at 1.2mm reaches 2A on 1–3 circuits — both above the PicoBlade’s 1.0A. So the PicoBlade’s case does not rest on current. It rests on the two-point contact design, the 125V rating (against 50V for JST GH at the same pitch), and the fact that one family covers wire-to-board and wire-to-wire with the same contact system.
- The voltage rating is where the PicoBlade separates from JST’s 1.25mm option. 125V against 50V is a material difference if your circuit runs above 50V. If it does, JST GH is not an option at any current.
Cable Assembly Options
KONNRA builds assemblies on the KR1250 interface in the standard harness configurations:
| Cable type | Description | Typical use |
|---|---|---|
| Single-headed | Housing on one end, bare wire leads on the other | Pigtail from a board header to a termination point |
| Same-side-head | Housing on both ends, same orientation | Extending a run between two boards |
| Reverse-side-head | Housing on both ends, reversed orientation | Routing through a fold or hinge |
| Wire-to-wire inline | KR1251 housing pair — the PicoBlade wire-to-wire variant | Inline connection with no board in between |
| Adapter and transition cables | KR1250 on one end, another interface on the other — for example PicoBlade to JST GH 1.25mm, or PicoBlade to SH 1.00mm | Where the two ends of a run use different series |
Two assembly notes that come straight from Molex’s own specification.
First, tie the cable at least 50mm from the connector edge and apply the tying force evenly across all wires. That distance exists so the terminals can float freely in their pockets; a tie closer than that pre-loads the contacts.
Second, if you are assembling in volume, Molex publishes separate Application Tooling Specifications per terminal part number rather than in the main product specification. If your harness house needs the crimp specification, it is on the individual terminal’s page, not in the connector datasheet.
Connector lead time is typically 2–3 weeks; wiring harness lead time is typically 3–4 weeks. Key materials are prestocked, and complete connector set samples can be delivered within 45 days.
➡️ Explore KONNRA wiring harness capabilities
Sourcing the Molex PicoBlade: What Procurement Teams Ask
Engineering decides that a connector will work. Procurement decides whether the supply chain around it is safe.
“Can you be a second source without changing our design?” That is what a documented cross-reference is for. The KR1250 is specified against the Molex PicoBlade 1.25mm system at component level — housing, terminal and all four wafer types — with matching 1.25mm pitch, 125V rating, two-point contact design and friction lock. We confirm equivalence against your specific part number, because wire gauge, orientation, mounting type and plating all change the answer.
“What are your lead times?” Connector production lead time is typically 2–3 weeks. Wiring harness lead time is typically 3–4 weeks. Key materials are prestocked.
“How long for samples?” Complete connector set samples can be delivered within 45 days. Where you need to validate crimp pull-out force or contact resistance before committing — both of which Molex specifies in detail on this series — sample harnesses can be supplied from the same process used in production.
“What qualifications do you hold?” ISO9001, ISO14001, IATF16949, ISO45001:2018, ISO13485, IPC620, and UL product and operational safety certifications. Automotive-grade series additionally hold LV214 and US CAR-2.
“How do we know the parts match your documentation?” A CNAS-accredited laboratory with 45+ sets of precision testing instruments, with dimensional and electrical verification data available on request. 95% of production processes carry full-line intelligent visual CCD inspection; automotive series receive 100% CCD inspection.
“Are you a manufacturer or a trader?” A manufacturer. Dongguan Konnra Electronics Co., Ltd., founded 2004, with in-house mould design, injection moulding, stamping, assembly, and inspection — so the connector and the cable assembly come from one quality system.
“What volumes can you support?” KONNRA reported 2025 sales of RMB 310 million, with connectors at 60% and wiring harnesses at 40% of the product mix, across four production bases with automation coverage exceeding 95%.
“Who else buys from you?” KONNRA states that it serves global cooperative clients including BYD, Volkswagen, and DJI.
➡️ Request the vendor qualification pack — certificates, test capability summary, product drawings, and a sample plan in one enquiry.
How to Get a Cross-Reference Check on Your MX1.25 Part Number
Most MX1.25 enquiries stall on the same thing: the buyer is not sure what information the supplier needs, so the enquiry never gets sent. Here is the complete list.
Send us:
- The original part number, if you have it — a housing such as
51021**00, a terminal such as500798025, or a plug assembly such as53048**60 - Circuit count — the Molex range is 2 to 15
- Wire gauge, and specifically whether it is AWG #26. Molex covers #26 to #32; the published KR1250 range is #28 to #32, so #26 needs to be raised explicitly
- Insulation outside diameter, not just the gauge. Molex allows up to φ1.0mm or φ1.04mm depending on terminal; KONNRA documents 0.4–0.8mm
- Plating finish required — flash or a specified gold thickness. Molex offers 0.38µm minimum as a distinct option, and the KONNRA documentation does not state a thickness
- Mounting and orientation — through-hole or SMT, straight or right-angle
- Wire-to-board or wire-to-wire. The wire-to-board cross-reference is KR1250; the wire-to-wire part is KR1251
- Your load current, so the AWG #32 0.8A question and the derating position can be settled rather than assumed
- Application and annual volume, so configuration, tooling and packaging can be matched to your programme
- A drawing or photo, if the part number is unreadable or the design has been reverse-engineered
When you send a part number, we will confirm four things against Molex’s own documentation: the terminal that matches your wire gauge and insulation diameter, the gold thickness you need, the wafer orientation and mounting type, and whether your design needs the wire-to-board or wire-to-wire variant. Those four are where an MX1.25 cross-reference most often goes wrong.
What you get back: a mapped KONNRA part number with the relevant product and engineering drawings, a specification comparison against your original part, and a sample and quote plan.
Engineer’s Pre-Release Checklist
Run this before you release a drawing for a PicoBlade-family connector.
- Pitch measured, not assumed. 1.25mm is Molex PicoBlade, Molex PanelMate, Hirose DF13, Hirose DF14 or JST GH. 1.20mm is Molex Pico-EZmate or JST ACH. None of them mate.
- Wire gauge confirmed inside the range both sides cover — Molex documents AWG #26 to #32; the published KR1250 range is AWG #28 to #32. If you are on AWG #26, raise it.
- Current checked per gauge, not per family — 1.0A at AWG #26, #28, #30, but 0.8A at AWG #32.
- Derating position established from your own board, not the datasheet table. Molex’s 2.5A-at-2-circuits figure is reference data for a 30°C rise with all circuits powered on a test board; Molex states that PCB trace design greatly affects the result.
- Sum of current across circuits checked against the maximum allowable, not just the per-circuit figure.
- Insulation outside diameter confirmed — up to φ1.0mm or φ1.04mm per Molex terminal, against KONNRA’s stated 0.4–0.8mm.
- Plating finish and thickness specified — flash or 0.38µm minimum gold. Note that KONNRA’s own page states both “Gold Flash/Tin over Nickel” in its specification table and “the contact area is tin-plated” in its advantages text.
- Mating durability considered — Molex specifies 30 cycles with gold plating; KONNRA publishes no figure. Design so this connector is not the one cycled in service.
- Retention sized against reality. Withdrawal force is 2.8N minimum at 2 circuits, falling to 1.8N by the 30th cycle. The friction lock is not a cable retention device.
- Cable tie placed at least 50mm from the connector, with even force across all wires.
- Service procedure checked for hot-mating. Molex states this product is not designed for mating or unmating under an active circuit.
- Terminal extraction procedure written. Molex advises fitting a new housing after extracting a terminal, because the lance deforms and retention drops sharply.
- Mating axis alignment part of the build instruction — straight, or under 10° if diagonal mating is unavoidable.
- Wire construction confirmed as tin-plated copper stranded, or raised for evaluation if it is not.
- Wire-to-board or wire-to-wire confirmed — KR1250 for wire-to-board, KR1251 for wire-to-wire.
- Wafer orientation and mounting type matched to your layout: DIP or SMT, straight or right-angle, and confirm the pick-and-place feature if the board runs through an SMT line.
➡️ Send us your drawing. We will review it against the KR1250 specification and come back with any mismatch we find — before you commit tooling. Submit a drawing for review
Why Source MX1.25 Connectors from KONNRA
Dongguan Konnra Electronics Co., Ltd. (brand: KONNRA) was founded in 2004 and is a National High-Tech Enterprise specialising in connector and wiring harness research, development, production, and sales.
Manufacturing depth. A vertically integrated process covering precision mould design and manufacturing, automation design, precision injection moulding, stamping, assembly, and CCD visual inspection. Automation coverage exceeds 95% across production lines.
Testing and validation. A CNAS-accredited laboratory with 45+ sets of precision testing instruments, and CAE analysis — contact nonlinear analysis, material nonlinear analysis, motion simulation, thermal field analysis, and high-frequency analysis — performed in Ansys 2022 R1. Verification data is available on request.
Inspection coverage. Full-line intelligent visual CCD inspection covers 95% of production processes, using Mitsubishi and Panasonic PLC control systems with FA25–35mm optical lenses and 5-megapixel cameras. Automotive connector series receive 100% CCD visual inspection.
Quality systems. ISO9001, ISO14001, IATF16949, ISO45001:2018, ISO13485, IPC620, and UL product and operational safety certifications, with automotive-grade series additionally certified to LV214 and US CAR-2.
Capacity and delivery. Production bases in Dongguan Wangniudun (30,000 m², 350+ employees), Dongguan Changan (10,000 m², 150+ employees), and Hunan Daoxian (2,600 m², 100+ employees), with regional offices in Beijing, Chongqing, Hunan, Shanghai, and Kunshan. Key materials are prestocked, and complete connector set samples can be delivered within 45 days. KONNRA reported 2025 sales of RMB 310 million, with connectors at 60% and wiring harnesses at 40% of the product mix, and has served global cooperative clients including BYD, Volkswagen, and DJI.
Custom and joint R&D. Where a standard part does not fit — the AWG #26 path, a specific gold thickness, a non-standard harness length, or a transition to another interface — KONNRA supports customer joint R&D customisation.
How to Identify Whether Your Connector Is a PicoBlade
If you are holding a connector and a drawing you cannot match, work through these in order:
- Measure the pitch. 1.25mm points at Molex PicoBlade, Molex PanelMate, Hirose DF13/DF14 or JST GH. 1.20mm points at Molex Pico-EZmate or JST ACH. 1.00mm points at Molex Pico-Clasp or JST SH.
- Count the positions. The PicoBlade is documented from 2 to 15 circuits. More than 15 is not a standard PicoBlade.
- Look at the contact geometry. The two-point contact design is the PicoBlade’s signature; a single-point contact at this pitch indicates a different series.
- Check the retention. The PicoBlade uses a friction lock — no positive latch. On the KONNRA side the mechanism is two locking bevels in the crimp housing engaging a locking window in the connector housing.
- Check whether the design is wire-to-wire. If both ends are cable, you have the wire-to-wire variant — KONNRA cross-references that as KR1251, not KR1250.
- Look for vacuum caps or a flat top on the board header. Their presence is consistent with the PicoBlade SMT design.
- Read the part number if there is one. 51021 is the receptacle housing, 53048 is the right-angle plug assembly, and the 5005 / 5007 prefix indicates a crimp terminal.
If you are still unsure, photograph the connector next to a ruler, with any part number markings visible, and send it to us. At this pitch, the measurement identifies the family; the part number identifies the variant.
Frequently Asked Questions
What is a Molex MX1.25 connector?
“Molex MX1.25” is trade shorthand for the Molex PicoBlade 1.25mm-pitch connector system — a single-row connector covering both wire-to-board and wire-to-wire, available in 2 to 15 circuits, with a two-point contact design and a friction lock, rated 125V AC (RMS)/DC and 1.0A per circuit at AWG #26–30.
Is Molex MX1.25 the same as PicoBlade?
Yes. Molex does not sell a product named “MX1.25” — the string describes the 1.25mm pitch, and it maps to the PicoBlade 1.25mm Connector System. Molex’s series numbers are 51021 for the receptacle housing and 53048 for the right-angle plug assembly.
What is the difference between PicoBlade and Pico-EZmate?
Pitch, current and configuration. PicoBlade is 1.25mm, rated 1.0A, at 125V, and covers wire-to-board and wire-to-wire. Pico-EZmate is 1.20mm, rated 1.5A, at 50V, wire-to-board only. They are not intermateable. Note that the smaller-pitch Pico-EZmate carries more current than the PicoBlade — do not assume the larger connector is the stronger one.
What is the current rating of the PicoBlade?
1.0A maximum per circuit at AWG #26, #28 and #30, and 0.8A at AWG #32. Molex also publishes a reference derating table by gauge and circuit count that runs up to 2.5A at 2 circuits with AWG #26 — but Molex marks those values as reference only, based on a 30°C temperature rise with all circuits powered, and states that PCB trace design greatly affects the result.
What does “reference derating” mean on the PicoBlade?
It means the values are not part of the rating. Molex’s derating table assumes a 30°C temperature rise, measures temperature rise in the crimp barrel area, and applies with all circuits powered on a test board. Molex explicitly notes that PCB trace design can greatly affect the result. If your design depends on a derated figure, establish it by temperature-rise testing on your own board.
What is the voltage rating of the PicoBlade?
125V AC (RMS)/DC. That is more than twice the 50V rating of JST’s GH series at the same 1.25mm pitch, which is a material difference if your circuit runs above 50V.
How many circuits does the PicoBlade come in?
Molex states the PicoBlade is “available in 2 to 15 circuits”, and both the derating table and the insertion/withdrawal force table run to 15. KONNRA documents the KR1250 as 2 to 16 positions — one beyond the original range.
What wire does the PicoBlade use?
AWG #26 to #32, with insulation outside diameter up to φ1.0mm on the 50058802* terminals and φ1.04mm on the 50079802* terminals. Molex specifies that the applicable wire is, in principle, tin-plated copper stranded wire, and that other constructions should be evaluated first.
Which PicoBlade crimp terminal do I need?
There are four: 500798020 and 500798025 for AWG #26–28, and 500588020 and 500588025 for AWG #28–32. The difference within each pair is the gold thickness — the 020 parts are gold flash and the 025 parts are 0.38µm minimum gold. At AWG #28 both families fit, so there the plating specification decides as much as the gauge.
What is the durability of the PicoBlade?
30 mating cycles with gold plating, per Molex. This is a low figure, and Molex’s own force table shows withdrawal force falling from 2.8N to 1.8N on a 2-circuit connector by the 30th cycle. KONNRA does not publish a cycle count for the KR1250.
What is the KONNRA equivalent of the PicoBlade?
KR1250 for the wire-to-board system, and KR1251 for the wire-to-wire variant. KR1250 is documented at 1.25mm pitch, 2 to 16 positions, 1A and 125V, offered as four wafer types plus a housing and a terminal.
Does the PicoBlade come in wire-to-wire?
Yes, and it uses the same contact system. KONNRA cross-references the wire-to-wire variant as KR1251. Note that KONNRA’s KR1250 page states the series supports both wire-to-wire and wire-to-board, while KONNRA’s own 1.25mm listing categorises KR1250 as wire-to-board — so confirm which part number applies to your design.
What is the two-point contact design?
A contact geometry in which each mating pair touches in two places instead of one, so that a single disturbed contact point does not open the circuit. Molex’s stated reason is that rugged applications can be subject to shock, vibration or rough handling that can dislodge the terminals and cause signal interference. It is the PicoBlade’s defining feature and the main reason to choose it over a single-point connector at a similar pitch.
Can the PicoBlade be mated under load?
No. Molex states that this product is not designed for mating and unmating under an active electrical circuit, and that doing so may cause a spark and product damage. If your service procedure disconnects this connector live, the procedure needs changing.
How far from the connector should I tie the cable?
Molex specifies a minimum of 50mm for a 2 to 15 circuit connector, with the tying force applied evenly across all wires, so that the terminals can float freely in their pockets. A tie closer than that pre-loads the contacts.
Can I reuse the housing after extracting a terminal?
Molex advises against it. Extracting a crimp terminal with a jig can deform the housing lance, and Molex states this can “reduce the terminal retention force enormously” after re-insertion. The guidance is to fit a new housing when repairing crimp terminals.
What is the operating temperature range of the PicoBlade?
−40°C to +105°C, and Molex states this includes terminal temperature rise. KONNRA documents the same range for the KR1250, so on this parameter the two agree.
What standards does the PicoBlade hold?
Molex lists UL File Number E29179. KONNRA’s product documentation states RoHS compliance, with UL certification asserted at brand level — if your qualification requires UL recognised status specifically for this part, ask for the file reference.
How long does it take to get samples?
KONNRA can deliver complete connector set samples within 45 days. Connector production lead time is typically 2–3 weeks and wiring harness lead time typically 3–4 weeks.
Start Your Cross-Reference Check
KONNRA supplies the KR1250 series as individual components or as complete pre-crimped cable assemblies, and builds adapter and transition harnesses to order.
- Request a quote — KR1250 and KR1251 pricing, MOQ and configuration options for your circuit count, orientation and mounting type
- Request a sample — complete connector set samples within 45 days
- Request cross-reference verification — confirm KR1250-to-PicoBlade equivalence against your specific part number, including the terminal for your wire gauge and insulation diameter
- Request AWG #26 confirmation — this gauge is inside Molex’s range and outside the published KR1250 range; ask before you design around it
- Request drawings — series engineering drawing, product specification and package specification
- Request a vendor qualification pack — certificates, test capability summary and quality documentation
- Request adapter harnesses — PicoBlade to JST GH 1.25mm, PicoBlade to SH 1.00mm, or another interface on the far end
- Submit a drawing for review — we will flag any specification mismatch before you commit tooling
Contact KONNRA Electronics
- Phone: (86)-769-85449875
- Email: info@konnra.com
- Address: No.6 Nanchang South Road, Chijiao, Wangniudun, Dongguan, Guangdong, China
- Contact us
➡️ Explore the full 1.25mm pitch range · Molex connector alternatives · Wire-to-board connector catalogue
Sources and method. Molex PicoBlade figures are taken from Molex’s published Product Specification 510211000-PS and Molex’s published product information: the 125V AC (RMS)/DC voltage rating; the rated current of 1.0A at AWG #26, #28 and #30 and 0.8A at AWG #32 with the associated insulation diameters of φ1.0mm max (50058802*) and φ1.04mm max (50079802*); the reference current derating table by gauge and circuit count with its stated conditions of a 30°C maximum temperature rise, measurement in the crimp barrel area, all circuits powered, and the caveat that PCB trace design greatly affects the result; the −40°C to +105°C ambient temperature range including terminal temperature rise; the 20mΩ maximum initial contact resistance, the 5mΩ maximum crimped-portion contact resistance, and the 40mΩ maximum contact resistance after environmental exposure; the 100MΩ minimum insulation resistance; the 250V AC (RMS) one-minute dielectric strength test; the 30-cycle durability with gold plating; the insertion and withdrawal force table by circuit count; the crimp pull-out, terminal insertion, terminal retention and header retention forces; the vibration and mechanical shock conditions; the temperature cycling, heat, cold, humidity, salt spray, SO₂ and NH₃ gas tests; the solderability and soldering heat conditions including 370–400°C for 5 seconds maximum with a soldering iron; the 265°C maximum wave solder temperature; the four crimp terminal part numbers 500588020, 500588025, 500798020 and 500798025 with their gold flash and 0.38µm minimum gold finishes and their AWG #26–28 and AWG #28–32 wire ranges; the 51021 receptacle housing series; the 53048 right-angle plug assembly series with its flash and 0.38µm gold variants; UL File Number E29179; the two-point contact design and friction lock; the vacuum caps and flat pick-and-place area on SMT headers; the available range of 2 to 15 circuits in tin- and gold-plated versions with through-hole and SMT mounting and vertical and right-angle orientations; the 50mm minimum cable tie dimension; and the usage notes covering hot-mating, applicable wire construction, terminal extraction, mating alignment, sympathetic vibration, washing, and current summation. The comparison-table figures for Molex Pico-EZmate, JST ACH, JST SH, JST GH and Hirose DF13/DF14 are taken from those manufacturers’ own published documentation where available, and from KONNRA’s published series data where noted. KONNRA KR1250 specifications, component pages and download links are taken from KONNRA’s published product and component documentation. Where the two sources disagree, or where a figure differs between two places on the same source, the difference is stated in this guide rather than smoothed over. Always confirm final dimensional and electrical requirements against the current manufacturer drawing for your specific part number.
