Reed Relays and
Electronics India Limited
Manufacturer of Reed Switches, Reed Sensors and Reed-based products
Reed Relays and Electronics India Limited Incorporated in 1971

UM-0018-M Ultra Miniature Reed Switch


UM-0018-M Ultra Miniature Reed Switch Drawing

All dimensions are in mm

UM-0018-M Cropped reed switch UM-0018-M SMD reed switch UM-0018-M Vertical Mount reed switch UM-0018-M horizontal mount formed reed switch

Click thumbnails to view Actuation Distances


5.0 mm glass size Omni-polar 5.0W Contact rating Does not require power for operation Normally Open, Form A contact  Sputtered Ruthenium contact Inert gas filled glass capsule Four formations Tin plated leads  RoHS Compliant and Lead-free  Not Sensitive to ESD


These highly sensitive, Form A type, Ultra miniature reed switches are designed for low power, high speed switching applications. The 5 mm glass version is built for use in very compact applications. The flattened leads are useful for orienting all reed switches in a batch, in one way, while soldering, welding etc., for maximum in-group sensitivity. The 5.0 mm glass version can be molded with a 0.25 mm wall around the glass capsule for use in hazardous industrial environments to withstand higher shock and vibration. This reed switch is completely Lead-free and conforms to the RoHS directive. The cropped version is suitable for smaller plastic housings and can be soldered to cables or used on SMT PCB’s with slots, the SMD version is suitable for reflow soldering on SMT PCBs, and the vertical and horizontal mount versions are suitable for mounting on through hole PCBs. Information on tolerances for these formations can be found here


Operate Range AT 7-20
Release Range AT 3-18
Contact Rating (max) W/VA 5.0
Switching Current (max) A 0.35
Carry Current (max) A 0.5
DC Switching Voltage (max) VDC 100
AC Switching Voltage (max) VAC 70
Breakdown Voltage (min) VDC 150
Contact Resistance (max) 200
Insulation Resistance (min) Ω 109
Capacitance (min) pF 0.2


Operate Time (max) ms 0.35
Bounce Time (max) ms 0.3
Release Time (max) ms 0.1
Resonance Frequency Hz >2000
Operating Frequency Hz 500
Operating Temperature °C -40 to +120
Shock Resistance (½Sin wave for 11ms) G 30
Vibration Resistance (10-2000Hz) G 20
Test Coil Code   717 102 003

Ordering Code

UM-0018-M-(Operate AT Band)-(Lead Formation Code)

Formation Code C S V H
  Cropped SMD Vertical Mount Horizontal Mount

Ordering Code Examples

UM-0018-M-7-12 denotes 7-12 Operate AT with unmodified leads
UM-0018-M-15-18-S denotes 15-18 Operate AT band with SMD formed leads

Handling of Reed Switches

Dropping Reed switch Reed Switches are sensitive devices that easily develop micro cracks in the glass to metal seals when subjected to external...Continue reading ->


Reed Switch cropping Reed switch leads may need to be cropped for use in custom plastic housings, after soldering with external cables. Cropping...Continue reading ->

Soldering Guide

Soldered Reed switch Manual Soldering of reed switch leads may be required when using custom plastic housing with external cables. The reed switches...Continue reading ->

Ferro-magnetic parts

Ferromagnetic parts Reed Switches use an alloy of Nickel and Iron with a few other elements that make the alloy ferro-magnetic and...Continue reading ->

Potting and Encapsulation

Dispensing unit When potting or encapsulating reed switch assemblies in custom housings, selection of materials are important. The specification of epoxy or...Continue reading ->

Other Special Configurations Available

Lower Static Contact Resistance
Dynamic Contact Resistance Limit
Higher Insulation Resistance
Special Release Limits
Gold plated leads


Although we can never restrict the use of a reed switch to a particular field, the following is a list of some of the applications that the UM-0018-M reed switch is known to perform well.

Reed Sensors in Capsule Endoscopy

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Reed switches and Reed Sensors in Defibrillators

Defibrillator Defibrillator Defibrillation is a treatment for life-threatening cardiac arrhythmia, or irregular heart beat. A portable defibrillator is a device that...Continue reading ->

Reed sensors for detecting key in ignition

key ignition Automobile Key An Ignition switch on an automobile comes in two types, a manual key or a start button as...Continue reading ->

Reed Sensors in Pediatric Feeding tubes

Pediatric feeding tube Pediatric Feeding Tube Pediatric Feeding tubes are used by nursing homes and hospitals on babies and young children. The insertion...Continue reading ->

Reed Sensors in Electric Car Chargers

E-car charger Electric Car Charging Station Electrical cars are designed to have a range of 250-300 kilometers on a full charge. To...Continue reading ->

Reed switches in Lightsabers

Light Saber Light Sabers are weapons used by the Jedi and the Sith, in the fictional Star Wars Universe, set...Continue reading ->

Reed sensors in canal hearing aids

Reed sensors in canal hearing aids In-canal Hearing Aid As widely known, a Hearing Aid is a device designed to improve hearing by making sound audible...Continue reading ->

Magnet sensors in Musical Greeting Cards

Reed switches in musical greeting card Greeting Card Even in the digital age of Smart phones, people do like to mail out or hand over greeting...Continue reading ->

Reed sensors in Notebook computer and PC desktops

Notebook computer Notebook Computer Tablet PCs, Notebook computers and Netbooks are part of personal life. Screen time on these devices is anywhere...Continue reading ->

Reed switches and Reed sensors in Spirometers

Spirometer Spirometer A Lung function test or Pulmonary Function test, PFT for short, is a system to evaluate the respiration system...Continue reading ->

Reed switches in Vagus Nerve Stimulators

Vagus Nerve stimulator Vagus Nerve Stimulator The Vagus nerve in the neck is one of the primary communication lines to the brain. For...Continue reading ->

Reed switches and Reed sensors in Pacemakers

pacemaker Pacemaker Artificial pacemakers are implantable devices that generate electrical impulses to the heart, to contract the muscles and regulate the...Continue reading ->
UM-0018-M 5W Ultra Miniature Reed Switches
5.0 mm x ø1.80 mm, Flattened leads, complete data sheet and technical specifications. Customers can safely use UM-1018-M in place of RI-80, RD-75AA or HSR-0035R
Brand: RRE
Manufacturer: Reed Relays and Electronics
Model: UM-0018-M
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