D6.5 Series Inductive Proximity Sensors (Ultra-Short 18mm / Y-Type / 35mm / 45mm)
6.5mm-diameter inductive proximity sensors for tight-clearance mounting where M8 sensors won't fit.
🔍 Click to enlarge · 1/8Technical Specifications
| Sensing Method | Inductive |
|---|---|
| Housing Diameter | D6.5 (cylindrical) |
| Body Length/Shape Options | Ultra-short 18mm / Y-type 18mm (right-angle) / 35mm / 45mm |
| Sensing Distance (Sn) | 1mm-2mm on 18mm/Y-type bodies; 1mm/2mm flush or 2mm/4mm non-flush on 35mm body; 1mm/2mm/3mm flush or 2mm/4mm/6mm non-flush on 45mm body |
| Mounting | Flush; T-suffix = non-flush (35mm/45mm bodies only) |
| Output Type | NPN / PNP, normally-open (NO) / normally-closed (NC) |
| Wiring | 3-wire (DC) |
| Operating Voltage | 10-30VDC |
| Detection Target | Metal |
| Response Time | 0.1ms typical (0.2ms on the 35mm 4mm non-flush model) |
| Switching Frequency | Up to 2KHz on shortest-range models, down to 400Hz on the 45mm 6mm non-flush model |
| No-Load Current | < 10mA |
| Max Load Current | 150mA |
| Leakage Current | < 0.01mA |
| Voltage Drop | < 1.5V |
| Ripple | < 10% |
| Switching Hysteresis | < 15% (Sr) |
| Repeatability | < 3.0% (Sr) / < 5.0% (Sr) |
| Protection Rating | IP67 |
| Operating Temperature | -25°C to +70°C |
| Temperature Drift | < 10% (Sr) |
| Short-Circuit Protection | Yes, with 180mA overload current protection point |
| LED Indicator | Yes |
| Housing Material | Nickel-plated brass |
| Standard Cable Length | 2m (longer lengths available on special request) |
Overview
This is a series of small-diameter (D6.5mm) cylindrical inductive proximity sensors built for applications where a standard M8 or larger sensor will not physically fit. The series covers four body configurations: an ultra-short straight barrel (18mm long), a right-angle "Y-type" version (18mm sensing head with a bent cable exit for side-clearance mounting), and two longer straight barrels (35mm and 45mm) that include non-flush (T-suffix) variants for extended sensing distance.
Every model is a 3-wire DC device (10-30VDC) with a choice of NPN or PNP transistor output and NO or NC switching logic, plus a built-in LED for visual status indication. It is intended for machine builders and OEMs designing compact fixtures, small indexing mechanisms, and tight-clearance detection points — for example inside jigs, small rotary tables, or narrow frame members — where a larger-diameter sensor cannot be mounted.
Features & Benefits
6.5mm Barrel Diameter for Tight-Clearance Mounting
Fits installation points too narrow for standard M8/M12 threaded sensors, without requiring a custom bracket adapter.
Four Body-Length/Shape Options in One Naming System
Ultra-short 18mm, Y-type 18mm right-angle, 35mm, and 45mm body types let integrators pick the exact physical footprint a design needs — including a right-angle cable exit for side-clearance installs — while keeping the same model-numbering and wiring logic across the whole family.
Sensing Distance Graded 1mm to 6mm with Flush and Non-Flush Options
Flush-mount versions can be embedded in metal without false triggering; non-flush (T-suffix) versions on the 35mm/45mm bodies extend sensing distance up to 4mm and 6mm respectively for applications with more mounting clearance.
Selectable NPN or PNP, NO or NC Output
Every sensing-distance/mount combination is available in NPN or PNP transistor output, each with NO or NC switching, so it can be matched directly to the target PLC/control-circuit input type without an interposing relay.
Fast Response (0.1-0.2ms) and Switching Frequency up to 2kHz
Response time of 0.1ms (0.2ms on the 4mm non-flush 35mm variant) with switching frequency up to 2kHz on the shortest-range models supports detection of fast-moving small parts or high-speed indexing without missed triggers.
IP67 Protection with Nickel-Plated Brass Housing
The nickel-plated brass housing and IP67 rating let the sensor tolerate washdown, dust, and coolant/splash exposure typical of production-floor mounting points.
Built-In Short-Circuit Protection with a 180mA Overload Trip Point
Reduces the risk of sensor damage from output shorts or wiring mistakes during installation and maintenance in confined spaces where miswiring is more likely.
-25°C to +70°C Operating Range with LED Status Indication
Suits standard indoor machine environments plus cooler/warmer plant conditions, and the LED gives an at-a-glance on/off status check for commissioning and troubleshooting inside tight assemblies where a meter probe may be hard to reach.
Applications
Models & Ordering Information
Ultra-Short 18mm (D6.5x18mm, Flush Mount)
Y-Type (D6.5x18mmY, Right-Angle Head, Flush Mount)
35mm (D6.5x30mm sensing head / 35mm overall)
45mm (D6.5x45mm)
How to Select
- Selection is driven by five variables encoded directly in the model number: body length/shape, sensing distance (Sn), output transistor type (N/P), switching logic (1/2), and mount type (flush / T-suffix non-flush).
- Ultra-short 18mm (straight, D6.5x18mm): most compact footprint, flush mount only, 1mm or 2mm sensing distance.
- Y-type 18mm (right-angle head with bent cable exit, D6.5x18mmY): same sensing distances as the ultra-short version, chosen when cable clearance requires a 90-degree exit instead of straight-out.
- 35mm (D6.5x30mm sensing head / 35mm overall): flush at 1mm/2mm, non-flush (T) at 2mm/4mm.
- 45mm (D6.5x45mm): flush at 1mm/2mm/3mm, non-flush (T) at 2mm/4mm/6mm — the widest sensing-distance range in the family.
- Flush (齐平) mount: sensor face can be embedded flush with surrounding metal without false triggering; available on all four body types.
- Non-flush (T-suffix) mount: only offered on the 35mm and 45mm bodies, and delivers longer sensing distance for the same body length, but the sensor needs a metal-free clearance zone around the sensing face.
- Choose output transistor type to match the sinking (NPN) or sourcing (PNP) input requirement of the target PLC/control circuit.
- Choose switching logic: suffix "1" for NO (signal on when target detected) or suffix "2" for NC (signal off when target detected).
- If line speed is high, check switching frequency: the shortest-range flush models switch fastest (up to 2kHz on 1mm ultra-short/Y-type/35mm/45mm models), while the longest-range non-flush 45mm model (6mm) switches at 400Hz.
- Model naming logic: D6.5 + detection-distance code (01/02/03/04/06) + N(NPN)/P(PNP) + 1(NO)/2(NC) + body length (18/35/45) + [T non-flush] + [Y right-angle] — e.g. D6.502N235T = D6.5 barrel, 2mm detection code, NPN, NC, 35mm body, non-flush mount.
📘 Need the full method? How to Choose a Proximity Sensor · NPN vs PNP Sensor Outputs Explained
When NOT to specify the D6.5 — and what to use instead
Detecting plastic, wood, liquid, or other non-metallic parts
Why not: This series is an inductive sensor with its detection target specified as Metal; it has no rated response to non-metallic targets.
Use instead: A capacitive proximity sensor series, which can detect non-metallic and liquid targets.
Application needs more than 6mm sensing distance
Why not: The widest sensing distance in this family is 6mm, and only on the 45mm non-flush (T-suffix) variant; the 18mm/Y-type bodies top out at 2mm.
Use instead: DAIDISIKE's economy M18/M30 inductive proximity sensors, rated up to 15mm sensing distance, or the JM-series M18/M30 connector sensors rated up to 40mm.
Need non-flush (extended-range) mounting on the ultra-short 18mm or Y-type body
Why not: Non-flush (T-suffix) mounting is offered only on the 35mm and 45mm bodies in this series; the 18mm and Y-type bodies are flush-mount only.
Use instead: The 35mm or 45mm D6.5 body when non-flush mounting and extra sensing distance are both required.
High-speed line needing faster than 2kHz switching
Why not: Switching frequency in this family tops out at 2kHz on the shortest-range flush models and falls to 400Hz on the 45mm 6mm non-flush variant.
Use instead: A photoelectric sensor, which typically supports higher switching frequencies for very fast small-part counting.
Panel wiring standardized on 2-wire DC or AC-powered proximity sensors
Why not: Every model in this series is a 3-wire DC device (10-30VDC); no 2-wire or AC-powered variant is listed for this series.
Use instead: Confirm 2-wire/AC availability directly with the factory before specifying, since this catalog line only lists 3-wire DC.
Machine-guard interlocking or any personnel-safety function
Why not: The spec sheet for this series lists no functional-safety or safety-rated certification.
Use instead: A dedicated safety-rated interlock switch or safety light curtain for guarding duty.
Specifications we do not publish yet
We only publish a figure once we are confident it is true. The items below are still being validated through further testing and real-world customer feedback, so for now we would rather leave them open than guess. If one of them matters to your design, ask us for the latest validated status.
- Correction factor for non-ferrous (aluminum/brass/copper) targets versus the rated steel sensing distance
- MTBF / expected service life
- Exact IP67 test conditions and duration
- Reverse-polarity or overvoltage protection beyond the stated overload trip point
- Weld-field (weld-immune) suitability
- Connector/cable pinout detail beyond the general wiring description
- Certification documents (stated as available on request, not published)
Frequently Asked Questions
What is the barrel diameter of this proximity sensor series?
What is the operating voltage range?
How is a 3-wire DC inductive proximity sensor of this type wired?
What is the difference between the ultra-short (18mm), Y-type, 35mm, and 45mm versions?
What sensing distances are available in this series?
What is the protection rating (IP rating)?
What is the operating temperature range?
Does this sensor have short-circuit protection?
What is the housing material?
What is the standard cable length?
Can I choose between NPN and PNP output, and NO or NC switching?
Can you provide certification documents for this sensor?
Works Well Together
On the same machine or line, D6.5 is typically ordered together with: Photoelectric Sensors · Relay & Timer Modules · Laser Switch Sensors
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Wire-adjustable BGS sensor with 2 mm or 15 mm spot, 10-300 mm range, published black/white differential distance.
A1J0101 Economical Input Amplifier Module
Optocoupler-isolated input amplifier that turns a low-voltage signal into a 250V AC / 10A relay output.
DDSK Laser Diffuse Reflective Sensor M12 / DK Laser Diffuse Reflective Sensor M18
M12/M18 threaded laser diffuse reflective sensor with a visible 650nm red laser for fast alignment.
Related Products in Proximity Sensors
Economy Inductive Proximity Sensors M8/M12/M18/M30 (JNX/JNS Series)
Economy 3-wire DC inductive proximity sensors M8/M12/M18/M30 - flush/non-flush, NPN/PNP, NO/NC, IP67.
Economy M4/M5/M6 Inductive Proximity Switches (Export-Grade)
Compact export-grade M4/M5/M6 inductive proximity switches in NPN/PNP, NO/NC for tight-space detection.
High-Quality Threaded M4/M5/M6 Inductive Proximity Sensors
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JD Series 3-Wire Connector-Type Inductive Proximity Sensors D6.5-M8 / D6.5-M12
6.5mm-probe inductive proximity sensor with a factory-fitted M8/M12 connector for tool-free field replacement.