Story Overview

  • Using high quality tools for automotive wiring jobs give you better results
  • Learn how Knipex and Klein Tools Automatic Wire Strippers work
  • Learn how to use the Astro Pneumatic Ratcheting Crimper Set
  • Learn why wire solder clamps are useful for making wiring connections

I’ll bet just about everyone reading this has wire cutters, strippers, and terminal crimpers in their toolbox. They’re absolutely necessary to do automotive wiring jobs.

I’ll also bet many of those tools are hardware store specials. I’ve got some too. At best they do a good-enough job. At worst they can destroy more wire than they cut, strip, or crimp. I’ve come to very much dislike ragged cuts on wire insulation and removing wire strands with the insulation, even if you select the right gauge jaw on the wire stripper.

The solution is the same as for any other job: use high-quality tools designed for the task. I scrolled through the Summit Racing website and upgraded my wiring tool arsenal with three items—the Knipex Automatic Wire Strippers, Klein Tools Katapult Automatic Wire Strippers, and the Astro Pneumatic Ratcheting Crimper Set. I used them to repair and slim down the wiring harness in my 1971 Corvette and they worked fabulously—check out that project in this article.

All I can say is that I should’ve gotten these tools a long time ago. Let’s take a closer look at them.

Knipex Automatic Wire Strippers

The Knipex and Klein Tool strippers slice and dice wire effortlessly, but they operate differently. Let’s look at the Knipex strippers first.

The wire is inserted into the Knipex tool from the front. Once the wire hits the internal stop, squeeze the handle to strip it. You can adjust the internal stop to shorten or lengthen the amount of insulation removed by using the lower red slider at the mouth of the tool. The stop can be adjusted from 6mm to 18mm (approximately 0.250- to 0.700-inch). You can strip multiple wires with the Knipex tool and they will all have exactly the same amount of insulation removed.

A red slider at the top of the jaws lets you set the tension of the cut. If you’re working with delicate wire, back off the jaw tension. The Knipex tool has a guillotine wire cutter at the top to strip wires from 24-gauge to 10-gauge.

Where this tool really shines for me is in tight quarters where I can only get at the front of the wire.

Klein Tools Katapult Automatic Wire Stripper

The Klein Tools Katapult wire stripper is as easy to use as the Knipex tool. You select the wire gauge and type (stranded or solid copper) on the side of the jaws and insert the wire through the left side of the tool. The sliding jaws automatically lock the wire in place. As you squeeze the handles, the tool strips the wire and ejects the insulation. Insulation is cut cleanly instead of being torn off, which is common with a cheap wire stripper.

The Katapult wire strippers have a cutter for stranded copper wire up to 10-gauge. Simply insert the wire from the backside and squeeze the handles. The cutter also handles 18-gauge to 8-gauge solid wire.

Astro Pneumatic Ratcheting Crimper Tool Set

The Astro Pneumatic wire crimpers work like ratcheting jaw crimpers used to make spark plug wires. The tool comes with jaws for these terminals:

  • Insulated terminals
  • Non-insulated terminals
  • Open-barrel terminals
  • Cord-end terminals

The jaws are held in place by a loaded check ball and are interchangeable—you can switch a matched set from one side of the tool to the other for right- or left-hand operation.

Using the tool is easy. Place the stripped wire into the terminal, then insert the terminal into the appropriate jaw. Squeeze the handles until the jaws release completely. A star adjuster on the face of the tool controls crimp pressure. Loosen the lock screw and turn the adjuster clockwise to decrease crimp pressure or counterclockwise to increase pressure. If the jaws do not release when fully squeezed, the pressure should be decreased. If you want to open the jaws part way through a crimp, there’s a little release lever on one of the handles.

Solder Clamps

One more tool you should acquire are wire solder clamps. They’re like having an extra pair of hands. The clamps I have are made by Lisle. The alligator clamps hold wire and small parts in various configurations to make soldering easier. The Lisle clamps have a magnetic base so you secure them to any iron or steel surface—a vise, for example.

All of these tools do a wonderful job of precision cutting, stripping, and crimping and helping with soldering. They cost a bit more but wow, do they ever do a nice job. Learn more from the accompanying photos.

Tool List

Knipex Automatic Wire Strippers KNX-12-62-180
Klein Tools Automatic Wire Strippers KLE-11063-W
Astro Pneumatic Ratcheting Crimper Tool Set APT-9477
Lisle Magnetic Soldering Clamps LIL-55000

Knipex Automatic Wire Strippers, Klein Tools Katapult Wire Strippers, and the Astro Pneumatic Ratcheting Crimping Tool
Like most gearheads, I have a collection of inexpensive wire cutters, strippers, and crimpers in my tool collection. They work but don’t always do a clean job. I recently upgraded to high-quality tools. From the left are Knipex Automatic Wire Strippers, Klein Tools Katapult Wire Strippers, and the Astro Pneumatic Ratcheting Crimping Tool. (Image/Wayne Scraba)
Feeding wire into Knipex Automatic Wire Strippers
The Knipex wire stripper tool is unique in that it strips from the end of the wire. That’s valuable because it can fit into tight quarters. Insert the wire as shown—it butts up to an adjustable stop. You can set the amount of wire insulation to be removed by moving the red button to the desired length. Once the strip is made, the jaws open automatically. (Image/Wayne Scraba)
Knipex Automatic Wire Strippers wire tension slider
The pointer indicates the slide button that determines the tension of the cut. This is important if you’re switching over from something beefy like 10-gauge wire to a smaller gauge. (Image/Wayne Scraba)
Knipex Automatic Wire Strippers wire cutter
The Knipex tool has a guillotine-style wire cutter at the top. The tool is made in Germany in case you were wondering. (Image/Wayne Scraba)
Klein Tools Katapult Wire Strippers wire gauge selector
The Klein Tools Katapult Wire Strippers work differently than the Knipex tool. You select the wire gauge along with the wire type (stranded or solid copper). Gauge and wire style are spelled out on the side of the jaws. (Image/Wayne Scraba)
inserting wire into Klein Tools Katapult Wire Strippers
The wire is inserted from the left side of the tool. A set of sliding jaws automatically lock the wire in place. Simply close the handle and the tool will strip the wire and remove the insulator in one fell swoop. It’s all very slick. (Image/Wayne Scraba)
Klein Tools Katapult Wire Strippers wire cutter
The Klein Tools wire stripper has a cutter. It works on copper wire only and can handle wire up to 10 gauge. Simply insert the wire from the backside and squeeze the handles. (Image/Wayne Scraba)
Astro Pneumatic Ratcheting Crimping Tool removable crimping jaws
Astro Pneumatic’s Ratcheting Crimping Tool works much like a set of quality spark plug wire crimpers do. It comes with six sets of removable jaws to handle various terminal types. You can reverse the jaws for left-hand operation. (Image/Wayne Scraba)
Internal steps on Astro Pneumatic Ratcheting Crimping Tool crimping jaw
The Astro Pneumatic tool’s jaws are machined with internal steps. This means the terminal can only be inserted one way. This allows for a perfect crimp. (Image/Wayne Scraba)
Setting crimp pressure on Astro Pneumatic Ratcheting Crimping Tool
The tool is adjustable for crimp pressure. This is set by loosening the small Phillips head screw and turning the star wheel. Turn it clockwise to decrease pressure and counterclockwise to increase it. (Image/Wayne Scraba)
Astro Pneumatic Ratcheting Crimping Tool jaw release latch
This is the jaw release latch on the Astro Pneumatic tool. Push it forward if you need to release the jaws mid-crimp. (Image/Wayne Scraba)
Lisle Wire Solder Clamps
Need an extra set of hands when soldering two wires together (and who doesn’t)? These Lisle Wire Solder Clamps have alligator clips that can be positioned at various angles. They have internal magnets and can be used on the stand or individually. The base is also magnetic. (Image/Wayne Scraba)
Keywords
Wire Crimper , Wire Strippers , wiring harness
Share this Article
Author: Wayne Scraba

Wayne Scraba is a diehard car guy and regular contributor to OnAllCylinders. He’s owned his own speed shop, built race cars, street rods, and custom motorcycles, and restored muscle cars. He’s authored five how-to books and written over 4,500 tech articles that have appeared in sixty different high performance automotive, motorcycle and aviation magazines worldwide.