How to Use a Wire Stripper Tool | Strip Any Wire Safely

One wrong squeeze can nick a conductor, creating a weak spot that later breaks inside a wall. Before stripping any wire that might be live, shut off the breaker and confirm zero voltage with a multimeter or non-contact tester. Assume every wire is energized until you personally prove otherwise.

Choose the Right Notch for Your Wire Gauge

Every manual wire stripper has a set of numbered notches or holes running along the jaws, each marked for a specific American Wire Gauge (AWG). Match the wire’s insulation diameter to the notch that fits snugly — the wire should sit in the slot without forcing, and the notch should not be so large that the insulation slides free when the jaws close. For example, a 14 AWG wire goes in the 14 notch. Self-adjusting automatic strippers sense the gauge and grip automatically, which is faster when you work with multiple sizes. Coaxial cable requires a dedicated coax stripper with adjustable blades that remove the outer jacket, shield, and dielectric in separate stages — never use a standard wire stripper on coax.

The Exact Strip Sequence (Step by Step)

1. Select the notch that matches the wire’s gauge. Hold the stripper so the notch aligns with the insulation.
2. Insert the wire to the depth you want stripped — typically about half an inch for most connections. Push the wire straight into the notch until the end contacts the jaw’s stop.
3. Squeeze the handles just enough to feel the blades cut through the insulation. Stop the moment you feel resistance change; over-squeezing cuts into the copper conductor. If the insulation does not cut fully, rotate the tool slightly to score the full circumference.
4. Twist and pull the stripper away from the wire end in a single smooth motion. The cut insulation ring should slide off cleanly. If it tears or sticks, the notch is too small or you did not rotate enough.
5. Inspect the conductor under good light. The copper should be bright, unbroken, and free of nicks or scratches. Any damage means you clip the end and start again — stressed conductors fail prematurely inside terminals.

If you are shopping for your first tool, our wire stripping and crimping tool roundup compares models that handle both jobs in one handle.

Common Mistakes That Ruin a Wire

The most frequent error is guessing the gauge rather than matching it. A notch one size too large does not cut the insulation deeply enough; one size too small digs into the copper. Squeezing too hard is the second most common — the correct pressure is firm but gentle, like cracking an egg. Failing to rotate the tool when the cut sticks leaves insulation partially attached, which then rips strands when you pull. Always check the bare conductor immediately after stripping; a nick you miss now becomes a fault later.

Safety Rules Before You Start

Power off the circuit at the breaker and test with a voltage tester before touching any wire — the one time you skip this is the one time the wire is live. Wear safety glasses because cut insulation fragments can fly. Do not force a stripper that feels stuck; either the notch is wrong or the tool needs adjustment. For coaxial cable stripping, use only a dedicated coax stripper with adjustable blades; the outer jacket and shield layers require precise depth control that standard strippers cannot provide.