About The Button Index
The Button Index is a free, neutral reference catalog for industrial push buttons, indicator lights, selector switches, and panel components. We help maintenance staff, engineers, and equipment managers find exact part numbers, compare specifications across manufacturers, and locate compatible replacement parts.
Why we exist
When a push button fails on a piece of equipment, you need to find the right replacement fast. But industrial component data is scattered across manufacturer PDFs, distributor sites with terrible search, and incompatible part numbering systems. The Button Index brings all of this together in one place — neutral, cross-brand, and spec-accurate.
What we cover
We catalog products from major manufacturers including:
- Schneider Electric — Harmony XB4, XB5 series
- Eaton — RMQ-Titan M22 series
- ABB — Modular Push Button (MP) series
- Siemens — SIRIUS ACT 3SU1 series
- Omron — A22 series
- IDEC — HW series
Frequently Asked Questions
What is a cross-reference in industrial components?
A cross-reference matches functionally equivalent parts across different manufacturers. For example, a Schneider ZB4-BA3 green flush push button is cross-referenced with an Eaton M22-D-G and ABB MP1-10G — they all fit a 22mm panel cutout and perform the same function, but use different part numbering systems.
What does the IP rating mean on a push button?
IP (Ingress Protection) ratings indicate how well a component is sealed against dust and water. The first digit rates dust protection (0-6), the second rates water protection (0-9). Common ratings for industrial buttons: IP65 (dust-tight, water jets), IP66 (dust-tight, powerful jets), IP67 (dust-tight, temporary immersion), IP69K (dust-tight, high-pressure steam). The rating applies to the front face when properly mounted.
What is a 22mm push button?
22mm refers to the panel cutout diameter — the size of the hole drilled in the panel where the button mounts. 22mm (sometimes listed as 22.5mm) is the most common standard size for industrial push buttons worldwide. Other common sizes include 16mm (compact) and 30mm (heavy-duty). All major manufacturers make 22mm buttons, making cross-brand replacement straightforward.
How do I find a replacement for a broken push button?
Start with the part number printed on the existing button or in the equipment manual. Enter it in our search to find exact matches and compatible cross-references. If you can't read the part number, filter by the specs you can identify: cutout size (usually 22mm), color, type (flush, extended, illuminated, emergency stop), and mounting style.
What is the difference between momentary and maintained push buttons?
A momentary push button springs back when released — the circuit is only active while you're pressing. A maintained (or latching) push button stays in position after pressing and must be pressed again to release. Most industrial start/stop buttons are momentary. Maintained buttons are used for on/off switching where the button state should be visible.
What is a contact block and do I need one?
A contact block is the electrical switching element that attaches to the back of a push button body. It contains the actual NO (normally open) or NC (normally closed) contacts. Most push buttons are modular — the button head, body, and contact block are separate pieces. When replacing a button, you often only need the head/body; the existing contact block can be reused if it's not damaged.