Inductive Proximity Sensors OEM Manufacturer China

Name: Inductive Proximity Sensors
Brand: SEGMENsensor

Watch: how inductive sensors work, how to wire them and how they are tested

**How an Inductive Proximity Sensor Works**One-minute animation: oscillator and coil, eddy currents in a metal target, the drop in oscillation amplitude that switches the output, and what sets the switching distance Sn.
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Transcript
How does an inductive sensor detect metal without contact? Inside the sensor, an oscillator drives a coil wound on a ferrite core. It creates a high-frequency magnetic field in front of the sensing face. When a metal target enters the field, eddy currents are induced in the metal. They draw energy from the field, and the oscillation amplitude drops. When the amplitude falls below the threshold, the trigger switches the output, and the LED lights up. The switching distance, Sn, depends on the sensor size and the target material. Mild steel gives the full rated distance. SEGMENsensor inductive sensors: M8 to M30, Sn 1–25 mm. Learn more at segmensensor.com.

**NPN vs PNP Sensor Wiring Explained**One-minute animation of 3-wire DC sensor wiring: brown +V, blue 0 V, black output; how a PNP output sources and an NPN output sinks current, and how to match the sensor to the PLC input.
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Transcript
NPN or PNP: which sensor do you need? A 3-wire DC sensor has a brown wire for +V, a blue wire for 0 V, and a black wire for the output. A PNP sensor sources current. When it detects the target, the output switches to +24 V, and current flows through the load to 0 V. An NPN sensor sinks current. When it detects the target, the output switches to 0 V. The load sits between +24 V and the output. So match the sensor to the PLC input: PNP for sinking inputs, NPN for sourcing inputs. SEGMENsensor proximity sensors: NPN or PNP, NO or NC. Learn more at segmensensor.com.

**Proximity Switches: Automatic Assembly, Ageing and Function Test**Production-line footage of SEGMENsensor proximity switches: reed sensing elements on automatic assembly machines, ageing in a high-temperature test chamber, and dedicated test stations that check the switching function and output of every sensor.
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Transcript
Proximity switches on the production line, from sensing element to final test. Reed sensing elements are fed into automatic assembly machines. Each element is positioned, formed and fitted automatically, one after another. Finished switches are aged in a high-temperature test chamber. Dedicated test stations then check the switching function and the output of every sensor. The readings on each station are checked before the sensors are packed. Every sensor tested · OEM volume supply. Request a quote at segmensensor.com.

H2-A — Sizes & Output Types

M12 M18 M30 Proximity Sensors — NPN PNP, 2-Wire 3-Wire

From 6.5 mm and M8 to M30. Every configuration is a fixed SEGMENsensor part number; NPN or PNP, normally open or closed, flush or non-flush.

SEGMENsensor SGI-GP M18 non-flush cylindrical inductive proximity sensor with M12 connector

6.5 mm · M8 · M12 · M18 · M30 Cylindrical

SGI-GP Series — General-Purpose Cylindrical Inductive Proximity Sensor

4,060 part numbers, flush or non-flush. Nickel-plated brass or stainless steel housing (PBT on some models). 2 m cable, M8 or M12 connector, or pigtail.

Sizes6.5 mm / M8 / M12 / M18 / M30

Sensing Dist.1–50 mm (size and mounting)

OutputNPN / PNP, DC 2-wire, AC, AC/DC

Supply5–36 V DC to 20–250 V AC/DC

Part numbersFamily pages

Get Quote Datasheet

SEGMENsensor inductive proximity sensor M18 with cable connection

Welding Environment

SGI-WR Series — Weld-Field Immune Inductive Proximity Sensor

For resistance and MIG/MAG welding cells: ignores constant and alternating magnetic fields up to 150 mT; PTFE-coated brass housing so weld spatter does not stick.

SizesM8 / M12 / M18 / M30

HousingPTFE-coated brass

Field immunityUp to 150 mT

OutputNO, NC or NO + NC

Part numbersSGI-WR page

Get Quote Datasheet

SEGMENsensor M18 all-metal inductive proximity sensor with stainless steel housing and M12 connector

All-Metal Detection

SGI-FM Series — All-Metal Inductive Proximity Sensor

469 part numbers in M8, M12, M18 and M30 with stainless steel housings, flush or non-flush, for targets in stainless steel, aluminium or copper. Square-housing SGI-GPQ part numbers on request.

SizesM8 / M12 / M18 / M30

Sensing Dist.1–13 mm (size and mounting)

OutputNPN / PNP, DC 2-wire

Supply10–30 V DC, 10–60 V DC

HousingStainless steel

Get Quote Datasheet

Specifications

M8, M12, M18 and M30 Proximity Sensors — General-Purpose SGI-GP Series Data

Values from the SEGMENsensor part-number table: 4060 checked SGI-GP part numbers. Each part number is a fixed configuration; the family pages list every one with filters and a one-page PDF datasheet. Published family pages: SGI-GP18U.

Parameter	SGI-GPD65 6.5 mm	SGI-GP08 M8	SGI-GP12 M12	SGI-GP18 M18	SGI-GP30 M30
Rated sensing distance, flush	1 / 2 / 3 / 4 mm	1 / 2 / 3 / 4 mm	2 / 4 / 6 / 8 mm	5 / 8 / 12 / 15 mm	10 / 16 / 22 / 25 mm
Rated sensing distance, non-flush	2 / 4 / 6 / 8 mm	2 / 4 / 6 / 8 mm	4 / 8 / 10 / 12 mm	8 / 16 / 20 / 23 mm	15 / 25 / 40 / 50 mm
Outputs	NPN, PNP, DC 2-wire	NPN, PNP, DC 2-wire	NPN, PNP, DC 2-wire, AC/DC	NPN, PNP, DC 2-wire, AC 2-wire, AC/DC	NPN, PNP, DC 2-wire, AC 2-wire, AC/DC
Supply	10–30 V DC, 5–36 V DC, 10–55 V DC, 10–60 V DC	10–30 V DC, 5–36 V DC, 10–55 V DC, 10–60 V DC	10–30 V DC, 5–36 V DC, 10–55 V DC, 10–60 V DC, 20–250 V AC/DC	10–30 V DC, 5–36 V DC, 10–55 V DC, 10–60 V DC, 20–250 V AC, 20–250 V AC/DC	10–30 V DC, 5–36 V DC, 10–55 V DC, 10–60 V DC, 20–250 V AC, 20–250 V AC/DC
Connection	2 m cable, M8 connector, M12 connector, M8 pigtail	2 m cable, M8 connector, M12 connector, M8 pigtail	2 m cable, M12 connector, M12 pigtail	2 m cable, M12 connector	2 m cable, M12 connector
Housing	Nickel-plated brass, Stainless steel	Nickel-plated brass, Stainless steel	Nickel-plated brass	Nickel-plated brass, PBT	Nickel-plated brass
Part numbers (flush / non-flush)	609 / 569	549 / 579	329 / 327	303 / 302	246 / 247

Switching frequency, protection class, operating temperature and dimension drawings depend on the part number and are sent with the quotation. All-metal (SGI-FM, 469 part numbers) and capacitive (SGC-GP) families use the same code structure.

H2-B — Protection & Environment

Proximity Sensor Selection by Environment

Choose the series by the condition at the mounting point: general purpose, high temperature, or all-metal detection.

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General Purpose
Normal machine surroundings

6.5 mm, M8, M12, M18 and M30, flush or non-flush
Nickel-plated brass or stainless steel housing
NPN / PNP 3-wire, DC 2-wire, AC and AC/DC outputs
Applications: machine tools, conveyors, packaging, assembly

→ SGI-GP series (general purpose) · M18 non-flush family

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High Temperature
Furnace, casting, plastics

Rated to +120 °C (T120) or +150 °C (T150); -30 °C low-temperature version (L30)
Special high-temp cable jacket (Teflon/silicone)
Stainless steel housing with PTFE sensing face
Applications: injection molding, die casting, furnace conveyors

→ SGI-HT high temperature series — 155 part numbers, T120 / T150 / L30

→ Special-environment series: high-pressure 1000 bar, +180 °C capacitive, 150 mT weld-field immune, 4–20 mA analog

⚙️

All-Metal Detection
SS, aluminum, copper

For targets in stainless steel, aluminium or copper
M8, M12, M18 and M30, flush or non-flush, 1–13 mm
Stainless steel housing; NPN / PNP or DC 2-wire
Applications: stainless food equipment, copper pipe, aluminium parts

→ SGI-FM series (all-metal)

Not sure which variant fits your application?

Tell us your target material, temperature, cable length, and PLC brand — our engineers will specify the exact model and output combination within 24 hours.

Ask an Engineer

Technology

How Inductive Proximity Sensors Work

Three stages: field generation → target detection → output switching. Entirely solid-state, no moving parts, rated for 100+ million operations.

Oscillator Generates EM Field

An LC oscillator circuit inside the sensor drives a coil behind the sensing face, generating a high-frequency electromagnetic field (typically 50 kHz–500 kHz). This field extends a defined distance in front of the sensor — the nominal sensing range Sn.

Target Induces Eddy Currents

When a conductive (metallic) target enters the EM field, the oscillating magnetic flux induces eddy currents in the target surface. These eddy currents absorb energy from the field, damping the oscillator amplitude. The closer the target, the greater the damping.

Comparator Triggers Output

A comparator circuit monitors the oscillator amplitude. When damping exceeds a threshold (target within sensing range), the trigger circuit changes the output state — NPN output sinks to GND, PNP output sources VCC. Switching frequency for each part number is given on its datasheet. Full step-by-step explanation →

H2-C — Applications

All-Metal Proximity Sensor OEM — 8 Industry Applications

From semiconductor automation to automotive welding — SEGMENsensor proximity sensors are specified for the harshest industrial environments.

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Semiconductor Automation

M8 and M12 stainless proximity sensors for wafer handling robots, FOUP openers, and cleanroom conveyor end-stops. Low-outgassing cable on request. Proximity sensor semiconductor automation — verified application.

🚗

Automotive Welding

SGI-WR weld-field immune sensors for resistance and MIG/MAG welding cells: they ignore magnetic fields up to 150 mT, and the PTFE-coated housing keeps spatter from sticking. Detects fixture clamps and part-in-fixture next to the weld gun.

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Conveyor & Packaging

M18 and M30 sensors for metal can detection, bottle cap counting and pallet presence on conveyor lines; non-flush M30 models reach up to 50 mm rated sensing distance.

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CNC & Machine Tools

Tool-change position feedback, spindle chuck confirmation, and door interlock sensing on CNC machining centers. Brass or stainless housing for coolant resistance. M12 connector for quick service.

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Hydraulic Cylinders

Cylinder rod or piston end-position detection with flush-mount M18/M30 sensors mounted on tie rods or end caps. Pairs with our LVDT displacement sensor for continuous stroke measurement.

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Press & Stamping

Sheet metal blank presence detection and die protection on hydraulic presses. M30 unshielded sensors with 25 mm sensing range for detection through press guard panels.

🍺

Food & Beverage

Stainless steel M8–M30 sensors for can and bottle presence on filling lines and stainless conveyor chain detection; the all-metal SGI-FM series detects stainless steel targets.

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Metal Parts Assembly

All-metal SGI-FM sensors for assembly verification where parts are stainless steel, aluminium or copper.

OEM Manufacturing

Inductive Proximity Sensor OEM Manufacturer — China Factory Since 2019

SEGMENsensor is a direct factory — not a trading company. Our Shenzhen manufacturing facility produces inductive proximity sensors in M8, M12, M18, M30, and square housing formats. We supply OEM equipment builders, integrators, and distributors in 30+ countries, with full CE and RoHS documentation and optional private-label packaging.

NPN / PNP / NO / NC — All Combinations

Every size available in NPN-NO, NPN-NC, PNP-NO, PNP-NC. 2-wire AC/DC variants also available. No tooling required to switch output type.

Custom Cable & M12 Connector

Standard 2 m PVC cable or M12 4-pin plug. Custom cable length (0.5 m–10 m), PUR/PTFE insulation, straight or right-angle M12 connector available.

CE / RoHS / ISO 9001 Certified

CE Declaration of Conformity per EN 60947-5-2 included with every shipment. RoHS 3 compliance certificate available. ISO 9001:2015 factory audit report on request.

Production Lead Time Per Quotation, OEM volume supply

Lead time for standard SGI-GP part numbers is confirmed with the quotation. Samples of 1–5 pcs ship in 5–7 days. Private-label OEM packaging (custom box, label) is quoted on request. RFQ reply within 24 hours.

Automatic proximity switch assembly line at the SEGMENsensor factory in Shenzhen, China

H2-G — Special Series

Special series: high-pressure, high-temperature and weld-field-immune inductive sensors — which one for which condition

The general-purpose SGI-GP series is for normal machine surroundings with no pressure at the sensing face. When the mounting point is inside a hydraulic cylinder, hot, next to welding current, or needs a measured distance instead of an on/off signal, choose one of the SEGMENsensor special-environment series below by that condition.

SEGMENsensor M18 high-pressure inductive proximity sensor mounted in a hydraulic cylinder end cap for end-of-stroke detection — SGI-HP high-pressure inductive sensor in an M18 hydraulic-cylinder housing: the sensing face sits in the oil and reads the piston at end of stroke.

SEGMENsensor weld-field immune inductive proximity sensor with PTFE-coated brass housing for welding lines — WR weld-field immune sensor: PTFE-coated brass housing resists spatter, electronics ignore welding fields up to 150 mT.

Select the series by the condition at the mounting point

Condition at the mounting point	SEGMENsensor series	Rating to check	Housing / sensing face	Sizes & output	Series page
Ordinary machine surroundings: coolant splash, dust, wash-down	SGI-GP general-purpose inductive	Rating per part number, sent with the quotation	Nickel-plated brass or stainless steel (PBT on some models)	6.5 mm / M8 / M12 / M18 / M30; NPN or PNP, NO or NC, DC 2-wire, AC, AC/DC	M18 series · flush-mount
Hydraulic oil pressure on the sensing face (cylinder end-of-stroke, valve blocks, presses)	SGI-HP high-pressure inductive	Pressure-rated face — contact us for pressure rating; -25 °C to +70 °C; IP67 / IP69K	Stainless steel housing, ceramic sensing face, O-ring sealed sensing head	M8 / M12 / M18; NPN or PNP	SGI-HP page
Ambient above +70 °C, metal target (injection molding, die casting, furnace conveyors, ovens)	SGI-HT high-temperature inductive	max. +120 °C (T120) or max. +150 °C (T150); L30 version for -30 °C	Stainless steel housing, PTFE sensing face, high-temperature cable	M8 / M12 / M18 / M30; NPN or PNP	SGI-HT page
Ambient above +150 °C, or the target is non-metal (glass, ceramic, hot plastic, powder)	SGC-HT high-temperature capacitive	max. +180 °C (T180); also T120 / T150; L30 / L40 cold versions	Adjustable sensing, PTFE face	M8 / M12 / M18 / M30; NPN or PNP	SGC-HT page
Next to resistance or MIG welding current (body shops, robotic weld cells)	WR weld-field immune inductive	Immune to constant and alternating magnetic fields up to 150 mT; -25 °C to +70 °C; IP67	PTFE-coated brass housing, spatter-resistant face	M8 / M12 / M18 / M30, 1–15 mm sensing; NPN, PNP or NO+NC	WR page
You need the distance to the target, not a switch (gap, runout, position)	Analog-output inductive	Measuring range up to 10 mm, 0.02 mm repeatability; IP67	Nickel-plated brass housing, PBT sensing face	D6.5 / M8 / M12; 4–20 mA, 0–10 V or dual	Analog page

Ratings above are taken from the SEGMENsensor series pages. Temperature codes (T120, T150, T180, L30, L40) are the last block of each part number, so the grade is visible on the label and on the order. Switching behaviour and marking follow IEC 60947-5-2 — Proximity switches ↗; ingress ratings follow IEC 60529 — IP Code ↗. If two conditions apply at once (for example pressure and heat), send both values and we will confirm which series, if any, covers them.

High pressure. A standard sensor mounted through a cylinder end cap fails because oil pressure deforms the face. The SGI-HP series uses a ceramic face and stainless housing sealed with an O-ring. Read how to choose a pressure-rated sensor for cylinder end position and how to machine the mounting hole and seal it. For continuous piston position instead of two end points, use a built-in magnetostrictive sensor.

High temperature. Order by the grade that covers the measured ambient at the sensor body, not the process temperature: T120 for max. +120 °C, T150 for max. +150 °C, capacitive T180 for max. +180 °C. The high-temperature selection guide explains cable choice, derating and the three most common ordering mistakes.

Weld field and analog. WR models keep switching next to welding transformers where a standard coil saturates. Analog models replace a switch with a 4–20 mA or 0–10 V distance signal; see 4–20 mA vs 0–10 V analog proximity sensors and our NPN / PNP wiring guide for the PLC side.

Need a special-environment sensor specified for your machine?

Send the mounting condition (pressure, ambient temperature, welding current or measuring range), thread size and output type. Standard SGI-GP part numbers ship from OEM volume supply with 1–5 sample pieces in 5–7 days and production lead time confirmed with the quotation; special-environment series are quoted per project. Every request is answered within 24 hours. Download the inductive proximity sensor datasheet (PDF) or browse the proximity sensor download page.

Get a Quote in 24 Hours

Section added 2026-09-29. Page content updated 2026-09-29.

FAQ

Frequently Asked Questions

Technical and sourcing questions from OEM buyers about inductive proximity sensors.

What is an inductive proximity sensor and how does it work?

An inductive proximity sensor detects metallic objects without contact by generating an electromagnetic field through a coil. When a metal target enters the sensing field, eddy currents are induced in the target, which damp the oscillator circuit. This change in oscillation amplitude triggers a switching output. Inductive proximity sensors work only on conductive (metal) targets and are not affected by dust, oil, or non-metal objects.

What is the difference between NPN and PNP proximity sensors?

NPN (sinking) proximity sensors switch the output to GND (0V) when activated — the output sinks current from the load to ground. PNP (sourcing) sensors switch the output to VCC (supply voltage) when activated — the output sources current to the load. NPN is common in Asia/China PLC wiring; PNP is more common in European systems. SEGMENsensor supplies both NPN and PNP in NO and NC configurations, all available from OEM volume supply.

What is the sensing distance of M12, M18, and M30 proximity sensors?

Rated sensing distances (Sn) of the general-purpose SGI-GP series: M8 = 1 / 2 / 3 / 4 mm flush, 2 / 4 / 6 / 8 mm non-flush; M12 = 2 / 4 / 6 / 8 mm flush, 4 / 8 / 10 / 12 mm non-flush; M18 = 5 / 8 / 12 / 15 mm flush, 8 / 16 / 20 / 23 mm non-flush; M30 = 10 / 16 / 22 / 25 mm flush, 15 / 25 / 40 / 50 mm non-flush. The distance is part of the part number. On non-ferrous metals (aluminium, stainless steel, copper) the operating distance is shorter; the all-metal SGI-FM series is made for those targets.

What is a weld-immune proximity sensor and when is it needed?

Weld-immune (or weld spatter resistant) proximity sensors are designed to resist electromagnetic interference from welding current and prevent metallic weld spatter from sticking to the sensing face. They use a stainless steel housing with anti-stick PTFE or ceramic coating on the sensing face, plus filtering electronics to ignore welding pulses. Required in all automotive body welding, robotic MIG/TIG/spot welding, and metal fabrication automation.

Can inductive proximity sensors be used in semiconductor fabs or cleanrooms?

Yes. SEGMENsensor supplies inductive proximity sensors for semiconductor wafer handling equipment, FOUP openers, and cleanroom automation. These sensors use stainless steel M8 or M12 housings with no outgassing materials, and can be supplied with vacuum-compatible cable. For semiconductor applications, confirm low-outgassing cable insulation (PTFE or special PVC) with our engineering team.

What is the supply voltage and current for M12 proximity sensor 10-30V NPN NO NC?

The output and contact are fixed by the part number. Example: SGI-GP12S-040PA-Q4 is a flush M12 sensor, 4 mm, PNP normally open, 10–30 V DC, M12 connector. Other M12 SGI-GP part numbers: NPN or PNP 3-wire models run on 10–30 V DC as standard, or 5–36 V DC and 10–55 V DC with the V36 / V55 codes; DC 2-wire models run on 10–60 V DC and AC/DC models on 20–250 V AC/DC. Load current and switching frequency are given on the datasheet sent with the quotation.

Is there a China factory for NPN PNP proximity sensors for OEM supply?

Yes. SEGMENsensor's Shenzhen factory (Registration No. 91440300MAEUXXQU04) manufactures NPN and PNP inductive proximity sensors from OEM volume supply. Sample orders of 1–5 pcs ship in 5–7 days. CE and RoHS certificates included. Custom cable length, connector type (M12 plug or cable) and housing material (nickel-plated brass, stainless steel or PBT, depending on size) are available. RFQ response within 24 hours.

What is the MOQ and lead time for custom OEM proximity sensors?

Qualification samples are 1–5 pcs for standard SGI-GP part numbers. Custom cable length, M12 connector, NPN/PNP/NO/NC combination, and housing finish are available, with production lead time confirmed with the quotation; samples of 1–5 pcs ship in 5–7 days. Full private-label OEM (custom housing color, logo, label) is quoted on request, OEM volume supply. Tooling-free customizations include cable length, connector, and output type. Every RFQ is answered within 24 hours.

Which proximity sensor series do I need above +70 °C?

The general-purpose SGI-GP series is for normal machine surroundings. For a metal target in an ambient up to +120 °C or +150 °C use the SGI-HT high-temperature inductive series, ordered as T120 (max. +120 °C) or T150 (max. +150 °C). Above +150 °C, or when the target is non-metal, use the SGC-HT high-temperature capacitive series with the T180 grade (max. +180 °C). Rate the sensor for the ambient temperature measured at the sensor body, not the process temperature.

Can a standard inductive proximity sensor be mounted inside a hydraulic cylinder?

No. A standard sensor has no pressure rating at the sensing face, so hydraulic oil pressure deforms the face and shifts or destroys the switching point. Use the SGI-HP high-pressure inductive series in M8, M12 or M18 with a ceramic face, stainless steel housing and O-ring seal; contact us for the pressure rating that matches your system. The mounting hole must be machined to the drawing on the SGI-HP page to keep the seal.

How do I read the temperature or environment rating from a SEGMENsensor part number?

The series prefix names the environment: SGI-HP is high-pressure inductive, SGI-HT high-temperature inductive, SGC-HT high-temperature capacitive, WR weld-field immune. The last block of the part number is the rating code: T120, T150 or T180 for the maximum ambient temperature, L30 or L40 for low-temperature versions, and an IP code such as L69 for IP69K on pressure-rated models. Each series page explains its full code, so the rating is visible on the label, the datasheet and your purchase order.

Inductive Proximity
Sensors – OEM
Manufacturer & Supplier

Key facts

Watch: how inductive sensors work, how to wire them and how they are tested

Made and tested in our factory

What is an Inductive Proximity Sensor?

M12 M18 M30 Proximity Sensors — NPN PNP, 2-Wire 3-Wire

M8, M12, M18 and M30 Proximity Sensors — General-Purpose SGI-GP Series Data

Proximity Sensor Selection by Environment

How Inductive Proximity Sensors Work

All-Metal Proximity Sensor OEM — 8 Industry Applications