Push Button & Selector Switch Ring Tags: The 22mm vs 30mm Legend Plate Guide
The little ring around a push button does a big job: it is the only thing telling an operator what happens when they press. When the factory paper insert fades or the legend no longer matches the machine, a custom engraved ring tag fixes it in seconds.
Important Disclaimer
This article is provided for general informational purposes only and does not constitute legal, safety, or professional compliance advice. Regulations, standards, and codes are subject to change and may be interpreted differently by authorities having jurisdiction (AHJ). Always consult with qualified safety professionals, licensed engineers, or legal counsel to determine the specific requirements applicable to your facility. TagBuilder is not responsible for any actions taken based on this information.
22mm or 30mm?
Operator devices come in two mounting-hole standards. 22mm (22.5mm) is the compact, IEC-style size used by most modern pilot devices. 30mm (30.5mm) is the heavy-duty, NEMA-style size common on older lines and in harsh-duty plants. Measure the panel cutout or check the device series — the ring tag must match the mounting hole, not the button cap.
Legend Conventions Operators Expect
| Device | Common legends |
|---|---|
| 3-position selector | HAND-OFF-AUTO, LOCAL-OFF-REMOTE |
| 2-position selector | ON-OFF, MAN-AUTO, FWD-REV |
| Push buttons | START, STOP, JOG, RESET |
| Pilot lights | RUNNING, FAULT, POWER ON |
| E-stop | EMERGENCY STOP (yellow background) |
Selector legends read across the top arc in position order, so a three-line tag places the words above the positions they describe. Emergency stop devices conventionally get a yellow legend field — that is what NFPA 79 expects around an e-stop actuator.
Shapes That Match Your Devices
Ring tags come in shapes that sit flush with each manufacturer family: traditional round plates, square-corner plates that match one major brand's square bezels, and round plates sized for another's standard bezels. A brand-compatible shape looks factory-original instead of retrofitted. Engraved plastic tags never fade the way printed film inserts do, and the legend cannot rub off under gloved hands.
Ordering Tips
Count your devices by size (22mm vs 30mm) and by line count (single legend vs 3-position). Order a few blanks in the same style for future changes — panels evolve, and matching tags keep the door consistent.
22mm and 30mm ring tags in brand-compatible shapes, engraved with your legends.
Or search the full range: all ring tags.
Photo credits: "Emergency stop button" by Cjp24 via Wikimedia Commons (CC BY-SA 3.0); "Emergency stop button on a control panel" by Shixart1985 via Wikimedia Commons (CC BY 2.0). Product images: TagBuilder.
