M3/M4/M5 Short-Body 15 mm Remote-Amplifier Inductive Proximity Switch
When even a 25 mm micro sensor is too long: 15 mm sensing heads with the amplifier moved out onto the cable.
- Sensing head only 15 mm long — Ø3, Ø4 or M5 × 0.5
- Remote amplifier barrel Ø6.5 × 30 mm, in-line on cable
- Rated sensing distance 0.6 – 1.5 mm by diameter
- DC 3-wire, NPN or PNP, NO or NC selectable
- Fitted (M3/M4) or nut-locked (M5) mounting
Why a remote amplifier?
Every self-contained inductive sensor has to fit its coil, oscillator, and output stage into one housing — which is why even "ultra-small" M3/M4 sensors are typically 25 mm long. In this series, only the coil stays at the detection point. The switching electronics live in a slim in-line barrel (Ø6.5 × 30 mm) that you can tuck into a cable channel or behind the fixture plate, anywhere along the Ø2.5 mm lead.
The result is a head you can bury in a 15 mm-deep bore: Ø3 and Ø4 versions are smooth (unthreaded) and are fitted into a reamed hole or clamp, while the M5 version keeps a fine M5 × 0.5 thread with lock nuts for adjustable, repeatable positioning. Typical homes are pneumatic gripper fingers, part-present checks in stamping and insert-molding jigs, and end-of-arm tooling where every millimetre of depth and every gram matters.
Already have room for a standard-length body? Then look first at our M3M4 ultra-small inductive proximity sensor — a self-contained 25 mm threaded design with published 10–30 V DC supply and IP67 sealing. This 15 mm remote-amplifier series is the specialist option for when that one does not fit.
How the Two-Piece Design Mounts
Only the 15 mm coil head occupies the fixture. The amplifier barrel sits anywhere convenient along the cable, then wires to the PLC as a normal DC 3-wire proximity input.
Model Selection Table
Codes are transcribed from the factory catalog. N = NPN, P = PNP; suffix 1 = normally open, suffix 2 = normally closed.
M3 head — Ø3 × 15 mm, unthreaded
| Model (NPN / PNP) | Sensing distance | Output logic | Dimensions |
|---|---|---|---|
| M30615N1 / M30615P1 | 0.6 mm | NPN NO / PNP NO | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M30615N2 / M30615P2 | 0.6 mm | NPN NC / PNP NC | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M30815N1 / M30815P1 | 0.8 mm | NPN NO / PNP NO | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M30815N2 / M30815P2 | 0.8 mm | NPN NC / PNP NC | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M31015N1 / M31015P1 | 1.0 mm | NPN NO / PNP NO | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M31015N2 / M31015P2 | 1.0 mm | NPN NC / PNP NC | Head Ø3 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
M4 head — Ø4 × 15 mm, unthreaded
| Model (NPN / PNP) | Sensing distance | Output logic | Dimensions |
|---|---|---|---|
| Ф4N1150.8 / Ф4P1150.8 | 0.8 mm | NPN NO / PNP NO | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N2150.8 / Ф4P2150.8 | 0.8 mm | NPN NC / PNP NC | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N11510 / Ф4P11510 | 1.0 mm | NPN NO / PNP NO | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N21510 / Ф4P21510 | 1.0 mm | NPN NC / PNP NC | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N11512 / Ф4P11512 | 1.2 mm | NPN NO / PNP NO | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N21512 / Ф4P21512 | 1.2 mm | NPN NC / PNP NC | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N11515 / Ф4P11515 | 1.5 mm | NPN NO / PNP NO | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| Ф4N21515 / Ф4P21515 | 1.5 mm | NPN NC / PNP NC | Head Ø4 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
M5 head — M5 × 0.5 thread × 15 mm
| Model (NPN / PNP) | Sensing distance | Output logic | Dimensions |
|---|---|---|---|
| M5N10.8 / M5P10.8 | 0.8 mm | NPN NO / PNP NO | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N20.8 / M5P20.8 | 0.8 mm | NPN NC / PNP NC | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N110 / M5P110 | 1.0 mm | NPN NO / PNP NO | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N210 / M5P210 | 1.0 mm | NPN NC / PNP NC | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N112 / M5P112 | 1.2 mm | NPN NO / PNP NO | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N212 / M5P212 | 1.2 mm | NPN NC / PNP NC | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N115 / M5P115 | 1.5 mm | NPN NO / PNP NO | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
| M5N215 / M5P215 | 1.5 mm | NPN NC / PNP NC | Head M5 × 0.5 × 15 mm; amplifier barrel Ø6.5 × 30 mm on Ø2.5 cable |
Note: M5 short remote-amplifier codes overlap with the threaded M5 × 25 mm standard series in the source catalog — the two differ by body form, so confirm the exact variant with our sales team before ordering. Supply voltage, IP rating, temperature range and switching frequency are not published for this series — contact the factory rather than assuming values from other series.
15 mm Remote-Amplifier vs Standard 25 mm M3/M4
| Feature | This series (15 mm, remote amplifier) | M3M4 ultra-small (25 mm, self-contained) |
|---|---|---|
| Head length | 15 mm | 25 mm |
| Electronics | Separate Ø6.5 × 30 mm barrel on cable | Built into the sensor body |
| Mounting | Ø3/Ø4 fitted in bore; M5 × 0.5 with nuts | M4 × 25 threaded, flush |
| Sensing distance | 0.6 – 1.5 mm (by diameter) | ≈ 1 mm (0.8 mm variant available) |
| Published supply / IP | Contact factory | 10–30 V DC, IP65/IP67 |
| Choose when… | Installation depth is under ~20 mm | A 25 mm threaded body fits the fixture |
Typical Applications
Pneumatic Gripper Fingers
Confirm part-grip directly at the fingertip where only a few millimetres of installation depth exist.
Gauging & Inspection Jigs
Seat-check metal parts in checking fixtures without enlarging the datum block for a long sensor body.
Insert-Molding & Stamping Tooling
Verify inserts and small blanks are present before the press cycle, with the amplifier kept clear of the die area.
End-of-Arm Tooling (EOAT)
Lightweight 15 mm heads add position feedback to robot EOAT without bulking up the tool plate.
Frequently Asked Questions
How is this 15 mm remote-amplifier series different from the standard M3/M4 ultra-small proximity sensor?
Two things: body length and architecture. Our standard M3M4 ultra-small sensor is a self-contained 25 mm body with the amplifier built in. This series shortens the sensing head itself to 15 mm — Ø3 or Ø4 unthreaded, or M5×0.5 threaded — and moves the amplifier electronics out into a separate Ø6.5 × 30 mm barrel that sits in-line on the cable, away from the detection point. If your jig has depth for a 25 mm body, the standard series is simpler; if 15 mm is all the space you have, this is the series to specify.
What sensing distances are available?
The M3 head is offered with 0.6 mm, 0.8 mm or 1.0 mm rated sensing distance. The M4 and M5 heads are offered with 0.8 mm, 1.0 mm, 1.2 mm or 1.5 mm. As with any inductive sensor, ratings apply to a standard mild-steel target; plan a smaller working gap for non-ferrous metals.
Are the heads threaded or smooth?
The M3 (Ø3) and M4 (Ø4) heads are smooth and unthreaded — they are slipped into a reamed hole or clamp and secured by the fixture, which is what allows the tiny diameter. The M5 head is threaded M5 × 0.5, so it can be locked with nuts like a conventional barrel sensor while keeping the 15 mm length.
How do I read a model number such as M30615N1?
Break it as M3 + 06 + 15 + N + 1: M3 diameter series, 0.6 mm sensing distance, 15 mm head length, NPN output, normally-open logic. P denotes PNP and suffix 2 denotes normally-closed. M4 and M5 codes follow the same distance / output / logic pattern.
What supply voltage, IP rating and response frequency does this series have?
The factory catalog for this specific 15 mm remote-amplifier series lists the wiring (DC 3-wire) and output options but does not publish the voltage range, ingress-protection rating, temperature range or switching frequency. Rather than quote figures from a different series, we ask you to confirm these with our engineers for your exact model — or consider the standard-length M3/M4 series, which is documented at 10–30 V DC and IP67.
Can these be used as safety interlocks for guards or personnel protection?
No. These are standard position sensors, not IEC 61496-certified safety components, and must not be used on their own for personnel protection. For guarding, pair the machine with a certified safety light curtain and safety relay instead.
What is the minimum order quantity and can you supply OEM versions?
Trial and sample quantities are normally workable for export customers, and OEM cable lengths or private labeling can be discussed for volume orders. Send the model codes you need (or your installation dimensions) through the contact page and our sales team will confirm MOQ, price and lead time for your region.