Proximity Sensor | 4mm Detection Switch | DC 10-30V NPN/PNP NO/NC
The SN04 is an inductive sensor for finding metal without touching it, used in automation. It reliably senses ferrous metals up to 4mm away. This sensor runs on 10-30V DC power, so it works with many ...
- Secure checkout
- All major cards
- Tracked delivery
Good to know
Questions about this product
- What's the sensing distance, and what materials will it detect?
- This is an inductive sensor with a fixed detection distance of 4mm. It's designed specifically to detect ferrous metals like iron and steel. It will not detect non-metallic objects like plastic, wood, or water.
- What's the difference between the NPN and PNP versions?
- The main difference is how they switch the output signal. NPN sensors (like the SN04-N) switch the negative (0V) line, which is common for PLCs from brands like Mitsubishi. PNP sensors (like the SN04-P) switch the positive voltage line, often used with Siemens PLCs.
- What power supply voltage does this switch need to run?
- These sensors are designed to run on a low-voltage DC supply. They operate on any voltage between 10V and 30V DC, making them suitable for most standard industrial control systems.
Proximity Sensors spec sheet (PDF)
Get a one-page sheet with full description, specifications, technical details, FAQs, price & SKU - handy to save, print, or share.
Not sure which one?
Compare with similar products
The same kind of product, in stock, in a similar price range.
This product: £29.99 · 4.9

Proximity Sensor | 4mm Detection Switch | DC 10-30V NPN/PNP NO/NC
- Price
- £29.99
- Rating
- 4.9(32)
- Sold
- 800+
- Stock
- In stock

Proximity Sensor | NPN NO 4mm Detection | DC 6-36V for CNC
- Price
- £35.99
- Rating
- 5.0(5)
- Sold
- 140+
- Stock
- In stock

Proximity Sensor | NPN Output | DC 6-36V Detection Switch
- Price
- £31.99
- Rating
- 4.9(111)
- Sold
- 1,000+
- Stock
- In stock

Proximity Sensor | 4mm NPN Normally Open | For CNC Automation
- Price
- £33.99
- Rating
- 4.9(12)
- Sold
- 268+
- Stock
- In stock

Proximity Sensor | M12 4mm Sensing | 5V DC for MCU Projects
- Price
- £35.99
- Rating
- 5.0(7)
- Sold
- 213+
- Stock
- In stock

Proximity Sensor | 5mm NPN Detection Switch | DC 6-36V 3-Wire
- Price
- £30.99
- Rating
- 4.9(38)
- Sold
- 600+
- Stock
- In stock

Proximity Sensor | NPN/PNP Metal Detection | M12 4mm Sensing Switch
- Price
- £31.99
- Rating
- 5.0(29)
- Sold
- 403+
- Stock
- In stock

Proximity Sensor M30 | 4-Pin Air Plug | 6-36V PNP NPN for PLC
- Price
- £33.99
- Rating
- 5.0(14)
- Sold
- 230+
- Stock
- In stock

Proximity Sensor | M18 Inductive Switch | 6-36V PNP NPN 4-Pin
- Price
- £31.99
- Rating
- 5.0(16)
- Sold
- 700+
- Stock
- In stock
Compare options
More Proximity Sensors
Explore the range
Popular in Industrial & Machinery
Complete the set






























