Turck proximity switches are among the most widely specified inductive sensors in factory automation, material handling and process plants. If you are an OEM, a maintenance engineer or a procurement specialist looking to buy Turck proximity switch stock at competitive prices, this 2026 sourcing guide explains exactly what to check before you place an order online, and where to find genuine new and surplus units without long factory lead times.
Why Turck proximity switches are so popular in industrial automation
Turck, a German sensor manufacturer, is famous for rugged cylindrical and rectangular inductive sensors used to detect metal objects without physical contact. Their product lines, such as the Uprox family and standard factor 1 sensors, deliver stable sensing distances across all metals, high switching frequencies and IP67/IP68 protection. For this reason the Turck proximity sensor is a standard replacement part on conveyor systems, packaging lines, CNC machines and robotic cells across Europe, Asia and the Middle East.
When a machine stops because a sensor has failed, you rarely have time to wait for a manufacturer quote. A reliable automation parts supplier with stock of both programmable controllers and sensor spares can usually ship the same day, which keeps your production line running.
Popular Turck proximity switch series you should know
NBB and NBN rectangular proximity switches
The NBB/NBN families are rectangular, often called block-style, inductive sensors used for position detection and end-of-travel sensing. Models like the surplus industrial sensor NBB20-L2-E2 are common on transfer equipment. When ordering, always match the part number printed on the housing with the datasheet, because a similar-looking sensor may have a different switching distance or output logic (PNP versus NPN).
BI and NI cylindrical proximity switches
The classic M8, M12, M18 and M30 threaded styles are coded BI (flush, embeddable) and NI (non-flush). Choosing the right diameter, sensing range and connector type (M12 quick disconnect or pre-wired cable) is critical. For pricing and availability of new or surplus PLC parts in the same BOM, check whether your supplier can quote a full kit including cable assemblies.
Uprox factor 1 sensors
Turck Uprox sensors provide the same sensing range for steel, aluminium and copper. They reduce stock-keeping because one sensor fits many applications, which is why maintenance teams keep several on the shelf next to their input/output modules.
How to choose the correct Turck proximity switch
Follow these five steps to avoid buying the wrong sensor:
1. Define the target metal and mounting. Flush (shielded) sensors can be embedded in metal; non-flush sensors need free space around the face.
2. Check the sensing distance. Standard ranges are 1.5 mm for M8, 4 mm for M12, 8 mm for M18 and 15 mm for M30 housings.
3. Verify output type. Most modern PLC input cards accept PNP (sourcing) 3-wire DC sensors, but confirm against your PLC controller specifications before ordering.
4. Select connection style. M12 connectors dominate new machinery; 2 m PUR cables are common for retrofit work.
5. Check certification. For hazardous areas choose ATEX/IECEx rated versions and verify the certificate applies to your zone.
Buying Turck sensors online: new, surplus or refurbished?
Three options exist when you need a Turck proximity switch for sale: factory-new from distribution, surplus new from excess inventory, or used/refurbished units. For critical safety circuits, always specify new or surplus-new units with original packaging. For older machines that use discontinued sensor types, surplus stock is often the only source, similar to how engineers source legacy SLC 500 modules long after the series ended.
A trustworthy surplus dealer will state the exact part number, sensing range, switching frequency, output logic and country of origin, and will back the sale with a written warranty. If the listing is vague, ask before paying.
Checklist for a reliable industrial sensor supplier
When evaluating a supplier for industrial proximity switches wholesale or single replacements, verify the following:
• They publish real stock photos with clear part numbers, not generic renderings.
• They provide datasheets and technical documentation.
• They ship worldwide and offer same-day dispatch on in-stock items.
• They give a 12-month or longer warranty on surplus components.
• They can source matched spare parts for your whole control panel, including PLC CPUs, I/O modules and PLC architectures knowledge if needed.
Why many buyers choose PLC-Hub for Turck and automation sensors
PLC-Hub is a supplier of new and surplus industrial automation components, covering PLCs, I/O modules and sensors from leading brands. The surplus automation parts programme includes Turck and Pepperl+Fuchs proximity sensors, and their installation instructions and user manual libraries help technicians fit parts correctly the first time. If your machine runs on an Allen Bradley or Rockwell platform, the Allen Bradley product series overview explains how sensors connect to discrete I/O cards.
Ordering multiple brands in one BOM
Modern control panels rarely use one brand. A typical bill of materials includes a Siemens or Allen Bradley PLC product series, Turck sensors on the field side and Phoenix Contact or Weidmuller terminals in the cabinet. Ordering from a supplier who covers several brands reduces freight cost and lead time. Ask for a consolidated quote that includes sensors, cables and MicroLogix-class controllers where applicable.
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Learn more about the technology behind sensors and controllers at Wikipedia – Proximity sensor and Turck official website.