59125 Series - Flange Mount Reed Sensor with Pins

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Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

A flange mount reed sensor 28.57mm x 19.05mm x 6.35mm (1.125" x 0.750" x 0.259") with integral terminal pins. Choice of normally open, normally open high-voltage or normally closed contacts. Its case design enables screw or adhesive mounting. Capable of switching up to 265Vac/300Vdc at 10VA. Available with a range of sensitivity options. Ideally suited for position and limit sensing, security, window and door alarm systems and linear actuator applications. Functions best with the 57125 actuator.

Note: The 57125 actuator is sold separately.


  • Magnetically-operated proximity sensor
  • Operates through non-ferrous materials such as wood, plastic or aluminum
  • Molded-in terminal pins accept push-on connector or wire-wrap
  • Case design allows screw-down or adhesive mounting
  • Customer-defined sensitivity


  • Well suited for usage in high-moisture and contaminated environments
  • Reed contacts last for millions of operating cycles under micro-controller voltage and current logic-level loads


  • Position and limit switching
  • Security
  • Linear actuators

Access specifications, certifications, check availability and order parts below

Catalog #Switching Power (W)Switching Voltage (V DC)Switching Current (A DC)Switching Voltage (V AC)Switching Current (A AC)Breakdown Voltage (V DC)Max Contact Resistance (Ω)Magnetic Sensitivity (AT)Nominal Activate Distance (mm)Switch TypeMin Operating Temp (°C)Max Operating Temp (°C)Max Operate Time (ms)Max Release Time (ms)StockSamplesCompare
59125-1-S102000.51400.352500.212 to 1812.5A:SPST-NO-4010511CheckOrder
59125-1-T102000.51400.352500.217 to 2311.3A:SPST-NO-4010511CheckOrder
59125-1-U102000.51400.352500.222 to 289.8A:SPST-NO-4010511CheckOrder
59125-1-V102000.51400.352500.227 to 338.9A:SPST-NO-4010511Check
59125-2-T103000.42650.34000.217 to 2311.3A:SPST-NO-2010511Check
59125-2-U103000.42650.34000.222 to 289.8A:SPST-NO-2010511CheckOrder
59125-2-V103000.42650.34000.227 to 338.9A:SPST-NO-2010511Check
59125-4-S51750.251200.182000.215 to 208B:SPST-NC-4010533Check
59125-4-T51750.251200.182000.220 to 257.2B:SPST-NC-4010533CheckOrder
59125-4-U51750.251200.182000.225 to 305.9B:SPST-NC-4010533Check

pdf icon Sensing Products Selection Guide

This guide provides an introduction to magnetic sensing and options for value-added custom design packages.

pdf icon Flow Sensing in Tankless Water Heaters Application Note

Reed switches and sensors are highly effective solutions for flow sensing applications that can be used for detecting the presence of fluid flow in a system or even measure the rate of fluid flow.

pdf icon Position and Level Sensing in Washing Machines

A most integral appliance in any home is a washing machine. Washing machines have helped made the chore of cleaning clothes quite effortless.

pdf icon Rice Cooker Lid Lock Application Note

The position sensing lid lock ensures that the lid is securely locked in place.

pdf icon Capacitive Loads Application Note

When there is significant capacitance in a reed sensor reed relay or reed switch circuit the peak current and energy switched by the reed contacts should be considered.

pdf icon Inductive Load Arc Suppression Application Note

When a reed switch or reed sensor is used to control an inductive device (relay coil solenoid transformer small motor etc.)

pdf icon Reed Switch and Reed Sensor Activation Application Note

Although a reed switch can be activated by placing it inside an electrical coil many reed switches and reed sensors are used for proximity sensing and are activated by a magnet.

pdf icon Reed Switch Extended Shock Capabilities Application Note

The maximum shock specifications in the Littelfuse catalog are very conservative for most switches smaller than the DRxxxx type. T

pdf icon Vibration Testing and Precautions Application Note

Littelfuse tests sinusoidal vibration according to Mil. Std. 202G Method 204D Test Condition G (10 � 2000 Hz frequency sweep at 30 G or 0.06 inch double amplitude whichever is less).

Part # Part Description RoHS Pb-free RoHS (2015/ 863/EU) Certificate REACH (SVHC’s) Declaration Halogen Free REACH (SVHC’s)
59125-1-S-00-0 59125-1-S-00-0 SENS RoHS No 02/20/2019 PbFree No 02/20/2019 No
59125-1-T-00-0 59125-1-T-00-0 SENS RoHS No 02/20/2019 PbFree No 02/20/2019 No
59125-1-U-00-0 59125-1-U-00-0 SENS RoHS No 02/20/2019 PbFree No 02/20/2019 No
59125-2-U-00-0 59125-2-U-00-0 SENS RoHS No 02/20/2019 PbFree No 02/20/2019 No
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