How to Strip an Electrical Wire Without Cutting the Copper

How to Strip an Electrical Wire Without Cutting the Copper

Stripping electrical wire cleanly is one of the most important skills in any wiring job. Nicked or cut copper strands reduce the conductor’s current-carrying capacity and can cause overheating at connections. The correct tool depends on the wire size and type — a dedicated wire stripper set to the correct gauge is far more reliable than using a utility knife or scissors.

Steps for Solid and Stranded Wire

• Select the correct gauge hole on the wire stripper — for 14 AWG use the 14 gauge slot, for 12 AWG use the 12 gauge slot
• Insert the wire into the correct hole, grip the stripper, and pull straight out along the wire axis — do not rotate the stripper while pulling, as this scores the copper
• For stranded wire, a slightly larger hole may reduce strand nicking — test on a scrap piece first
• The correct strip length for a wire nut or lever connector is marked on the connector — typically 11-13mm; for screw terminals, strip to match the terminal lug depth
• After stripping, inspect the copper — any cut strands or deep scoring means re-strip further up the wire

What to Avoid

• Using a knife to score and snap the insulation — this almost always nicks the copper
• Using a too-small gauge hole, which cuts into the conductor
• Stripping aluminum wire without anti-oxidant compound — stripped aluminum begins oxidizing immediately and must be protected at the connection point

EZSMART electricians are trained in proper wire preparation for all connection types. Contact us for wiring, panel work, or any electrical project across Ontario.

Amir Azimipour

Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp