Spring-Return Push Buttons Selection Guide
When selecting spring-return push buttons, compare Ø22 mm mounting diameter, NO/NC contact blocks, illuminated vs non-illuminated heads and IEC 60204-1 color coding.
This guide explains what to look for when choosing products in the Spring-Return Push Buttons category for machine control stations, operator pendants and electrical distribution panels.
Momentary operation and NO / NC contact blocks
Spring-return (momentary) push buttons actuate only while pressed and automatically return to their rest position when released. In self-holding contactor circuits, Start buttons use a normally open (1 NO) contact block, whereas Stop buttons use a normally closed (1 NC) contact block for wire-break fail-safe operation. Additional snap-on NO/NC contact blocks can be stacked on the mounting adapter to switch multiple circuits simultaneously.
Mounting diameter (Ø22 mm), IEC 60204-1 color coding and LED voltage
Industrial panel cutouts standardize on Ø22.5 mm. Under IEC 60204-1 machine safety conventions, Green indicates Start/On, Red indicates Stop/Off, Yellow indicates intervention/abnormal condition reset, and Blue/White/Black are used for reset or auxiliary jog functions. When selecting illuminated spring-return push buttons, match the integrated LED module voltage (24 V AC/DC or 230 V AC) to the control circuit supply.
Spring-return push button comparison table
| Selection Criterion | Start / Jog Push Button | Stop Push Button | Illuminated Spring-Return Button |
|---|---|---|---|
| Standard Color | Green (or White/Black) | Red | Green, Red, Yellow, Blue, White translucent lens |
| Contact Block | 1 NO (Normally Open) | 1 NC (Normally Closed) | 1 NO or 1 NO + 1 NC + integral LED block |
| Actuator Profile | Flush head — prevents accidental actuation | Flush or extended head for quick access | Flush illuminated lens head |
| Bezel & Protection | Plastic or metal bezel, IP65 / IP66 front | Plastic or metal bezel, IP65 / IP66 front | 24 V AC/DC or 230 V AC LED module, IP65 |
Frequently asked questions
What is the difference between a spring-return and a latched (maintained) push button?
A spring-return button remains actuated only while held down and springs back immediately upon release, making it ideal for contactor seal-in pulses and jog commands. A latched button stays locked in position until pressed or twisted again.
Why are Stop push buttons wired with normally closed (NC) contacts?
With an NC contact, the control loop remains energized during normal operation; pressing the button—or suffering a broken control wire—opens the circuit and safely stops the machine (fail-safe design).
Should I choose plastic or metal bezel push buttons?
Plastic bezel push buttons offer double insulation and corrosion resistance for general control panels and polycarbonate enclosures, while metal bezel series provide superior mechanical impact durability on heavy machinery.