Tap Panel Knockouts Out Side-to-Side — Never Toward the Next Ring

The Problem

Panel and disconnect knockouts look like you should just hit them — and that's how the concentric rings around them get bent or broken, leaving a hole too big for the connector and a gap that isn't legal to leave open. The metal gives clues about where it wants to break; most people never look for them.

The Technique

An electrician's sequence, with only a flathead screwdriver and lineman's pliers:

1. Use a sturdy flathead — an impact-rated one. A light-duty screwdriver's tip deforms and chews the metal instead of driving it.
2. Find the divots. The small dimples stamped around the knockout are the engineered weak points — those are your targets.
3. Tap like an archaeologist, not a demolition crew. Light hammer taps on the divots to start the knockout moving.
4. Rock it side to side. Tap one side, then the other, back and forth — the tabs fatigue and let go cleanly. Don't work upward into the surrounding ring: pressure that direction breaks the next ring out, the one you wanted to keep.
5. Twist out the last connection with lineman's pliers once the slug is hanging, and fit your connector.

If a ring does break, spacer (reducing) rings exist to rebuild the opening — fit one flush, oriented correctly, and carry on.