A screw extractor is a specialized hand tool designed to remove broken, stripped, rusted, or seized screws, bolts, and studs that cannot be removed using conventional screwdrivers or wrenches. It is typically manufactured from hardened high-speed steel (HSS), alloy steel, or chrome vanadium steel to provide exceptional strength, wear resistance, and durability. Most screw extractors feature a tapered, reverse-threaded (left-hand spiral) design that bites into the damaged fastener as it is turned counterclockwise. Screw extractors are commonly supplied in sets of different sizes to accommodate a wide range of fastener diameters and are widely used in automotive repair, machinery maintenance, construction, engineering workshops, and general equipment servicing.

Operation

To operate a screw extractor, first clean the damaged fastener and, if necessary, apply a penetrating lubricant to loosen any corrosion. Using a centre punch, mark the centre of the broken or stripped screw, then drill a pilot hole of the recommended diameter into the fastener using an appropriate drill bit. Insert the correctly sized screw extractor into the pilot hole and turn it counterclockwise using a tap wrench, adjustable wrench, or T-handle. As the reverse threads grip the inside of the fastener, the extractor gradually loosens and removes the damaged screw. Once the screw has been extracted, clean the threaded hole and inspect it for any damage before installing a replacement fastener. After use, clean the extractor, inspect it for wear or damage, and store it in a dry, protective case to maintain its performance and service life.