A screw extractor set is a collection of specialized tools designed to remove broken, stripped, or damaged screws and bolts from a workpiece without damaging the surrounding material.
Essentially, when a screw head is too damaged to grip with a screwdriver or other tool, a screw extractor provides a way to grip the screw and back it out of its hole.
Components of a Screw Extractor Set
While specific sets may vary, a typical screw extractor set includes:
- Screw Extractors (or Easy Outs): These are hardened steel tools, often tapered or straight, with reverse threads. The extractor is designed to bite into the damaged screw head and, as it's turned counter-clockwise, force the screw to unscrew from its hole.
- Drill Bits: These are used to create a pilot hole in the center of the damaged screw head. The size of the drill bit is typically matched to the size of the screw extractor to be used.
- Sometimes a Tap Handle (T-Handle Wrench) or Socket Adapter: Provides leverage and control when turning the extractor.
- Case: A container to store and organize the components.
How Screw Extractors Work
The general process for using a screw extractor is as follows:
- Prepare the Screw: Using a drill bit (usually included in the set), create a pilot hole in the center of the broken screw. This helps guide the extractor and provides a starting point.
- Insert the Extractor: Select the appropriate size screw extractor for the screw you are trying to remove. Insert the extractor into the pilot hole.
- Turn the Extractor: Using a tap handle or socket adapter, slowly and firmly turn the extractor counter-clockwise. The reverse threads of the extractor will bite into the screw head.
- Remove the Screw: As you continue to turn the extractor, the damaged screw should begin to unscrew from its hole.
Important Considerations When Using Screw Extractors
- Choose the Right Size: Using an extractor that's too large can damage the threads in the hole the screw is in. Using one that's too small might not provide enough grip.
- Apply Even Pressure: Avoid applying excessive force, which could break the extractor or further damage the screw.
- Use Lubricant: Applying a penetrating oil or lubricant can help loosen the screw and make removal easier.
- Consider Alternatives: Before resorting to a screw extractor, explore other options like using a rubber band or steel wool to improve grip on the screw head with a screwdriver. Sometimes, cutting a new slot into the screw head with a rotary tool allows for removal with a flathead screwdriver.
Different Types of Screw Extractors
- Spiral Flute Extractors: These are tapered extractors with spiral flutes that dig into the screw as they are turned.
- Straight Flute Extractors: These have straight flutes and are often used with a tap wrench.
- Square Extractors: These have a square end for use with a wrench.
