UL 508A Industrial Control Panel Build
Proper push button installation ensures that the operator interface remains stable and aligned over time.
Most industrial push buttons feature a small tab that fits into a "keyhole" or "notch" at the top of the mounting hole. Without this notch, the button can spin when pressed or turned, leading to loose wiring and misaligned labels.
Methods for Creating Notches
The File Method (Not Recommended): Using a small metal file to hand-cut the notch. This is slow and carries a high risk of the file slipping and scratching the panel face.
The Keyhole Nibbler (Professional Method): A hand tool designed specifically to punch a clean rectangular notch into the sheet metal. It provides a consistent depth and width for 22mm and 30mm standards.
Laser Cutting: For production-grade panels or trainers, having the notches pre-cut during the manufacturing process ensures perfect alignment every time.
Pro-Tips for Success
Mark the Top: Always mark the exact top of the hole before punching. Eyeballing the center often results in crooked buttons.
The Right Tool: Use a dedicated push button wrench rather than pliers or channel locks. This prevents marring the plastic or metal locking nut and ensures the button is seated firmly against the panel.
Part Numbers to Purchase