How to Use a Wire Stripper Correctly

Stripping wire correctly is a fundamental electrical skill — whether you're replacing an outlet, installing a light fixture, or working on a DIY electronics project. Done right, it takes seconds and leaves a clean, undamaged conductor. Done wrong, it nicks the wire and creates a potential failure point. Here's how to do it correctly.

What Is a Wire Stripper?

A wire stripper is a hand tool designed to remove the plastic insulation from electrical wire without cutting or nicking the metal conductor inside. Most wire strippers also include wire cutters, crimpers, and bolt cutters built into the same tool.

Recommended Wire Stripper

The haisstronica Wire Stripper and Crimping Tool (AWG 24-10) is an automatic stripper with a ratchet crimper — strips wire cleanly in one squeeze without adjusting for wire gauge. Works with AWG 22-10 heat shrink connectors. Check it on Amazon →

Understanding Wire Gauge (AWG)

Wire gauge determines which notch on the stripper to use:

AWG 14: Standard household circuits (15-amp)
AWG 12: Kitchen and bathroom circuits (20-amp)
AWG 10: Dryer, AC, and high-draw appliances (30-amp)
AWG 18–22: Low-voltage, speaker wire, electronics

Important: The higher the AWG number, the thinner the wire. Using the wrong notch will either not cut through the insulation (too large) or nick the conductor (too small).

How to Identify Wire Gauge

Check the wire jacket — the gauge is usually printed on the insulation (e.g., "14 AWG" or "12/2")
Match the wire to the labeled notches on your stripper
When in doubt, test on a scrap piece first

Step-by-Step: How to Strip Wire Correctly

Turn off the power at the circuit breaker before working on any electrical wire. Verify with a non-contact voltage tester.
Identify the wire gauge from the jacket label.
Select the correct notch on the wire stripper that matches the gauge.
Insert the wire into the correct notch, about 3/4" from the end (or your desired strip length).
Close the handles firmly — the notch cuts through the insulation without touching the conductor.
Rotate the stripper slightly (half turn) to score around the full circumference of the insulation.
Pull the stripper toward the wire end while maintaining grip — the insulation slides off cleanly.
Inspect the conductor: It should be bright, unscratched copper or aluminum. Any nicks mean you used the wrong notch — cut off the damaged section and try again.

How Much Insulation to Strip

Wire nuts: Strip 3/4" for most wire nut connections
Screw terminals (outlets, switches): Strip 3/4" and form a hook with needle-nose pliers
Push-in connectors: Strip exactly the length shown on the connector's strip gauge (usually 1/2")
Crimp connectors: Strip to match the connector barrel length

Safety Rules for Electrical Work

Always turn off the circuit breaker before working on any wiring
Verify power is off with a non-contact voltage tester before touching any wire
Wear insulated gloves when working near live circuits
Never work on live wires — even low-voltage wires can cause injury
If in doubt about any electrical work, consult a licensed electrician

Common Mistakes to Avoid

Using the wrong gauge notch (nicks the conductor)
Stripping too much insulation (exposes conductor unnecessarily)
Stripping too little (poor connection)
Not turning off the power before stripping
Using a utility knife instead of a proper wire stripper (very easy to nick the conductor)
Ignoring nicked conductors — always cut off and re-strip

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