Legend Plate Guide: 22mm and 30mm Engraving

Legend plates are small, but on a control panel they carry the whole operator interface — what each pushbutton, selector, and pilot light does. Get the sizing or text wrong and the panel is confusing at best and unsafe at worst. Here's what legend plates are, how they're sized, and how to order them clean.

What a legend plate is

A legend plate is the engraved plate mounted behind a panel operator — a pushbutton, selector switch, or indicator light — that labels its function (START, STOP, FORWARD/REVERSE, RUN, a numbered legend). It sits between the operator and the panel face and is engraved for permanent, high-contrast identification.

22mm vs 30mm

The two standard operator sizes are 22mm and 30mm, referring to the mounting-hole diameter of the device. Match the plate to your operators: 22mm is common on modern control gear, 30mm on heavy-duty and legacy equipment. Ordering the wrong size means the plate won't seat correctly, so confirm the operator size from the panel bill of materials.

Shape and holes

Legend plates come in standard rectangular and round formats and custom shapes, with single- or double-hole configurations for the operator and any anti-rotation feature. Specify the cutout so the plate fits the device and mounts flat.

Text and color conventions

Keep legends short and unambiguous, follow any facility or ANSI safety color convention (high-contrast pairs, red for stop/emergency), and size text to the plate and viewing distance. Consistency across the panel matters as much as the individual plate.

Ordering from a panel BOM

The fastest path is a bill of materials or a list with a row per plate — operator size, text, color, quantity. Plates can be engraved and sorted by panel section so a builder receives them organized for assembly rather than loose.

Custom Phenolic Labels engraves 22mm and 30mm legend plates for pushbuttons, selectors, and pilot lights, sorted by panel section and shipped to your build location.

Plan the complete identification package

Use these connected guides and services to confirm the material, code reference, mounting method, and order details: Engraved Legend Plates, and Mount Engraved Labels So They Last.