Mayhew 37331 Screw Extractor Set 4 Piece 13/16 15/32 21/32 9/16 Drill Sizes

Four-Piece Straight-Flute Extractor Set

This Mayhew 37331 set contains four straight-flute screw extractors designed to remove broken bolts and studs. The pieces cover drill sizes of 13/16 in, 15/32 in, 21/32 in and 9/16 in for bolt sizes of 1-1/8 in, 1-3/8 in, 3/4 in and 7/8 in. Each extractor is made from high-speed steel and measures 7 1/4 in overall length. The set is supplied in a pouch for organisation.

Straight-Flute Limitation

Straight-flute extractors require a pre-drilled hole in the centre of the broken fastener and rely on friction to grip the walls. They cannot engage a fastener that has snapped off flush without a drilled pilot hole. The design is not suited for extracting broken pipe taps or spiral-flute applications where a left-hand cutting action is preferred. Users must ensure the drilled hole matches the specified drill size for each extractor to avoid slippage.

High-Speed Steel Material

The extractors are machined from high-speed steel, which provides the hardness needed to bite into hardened bolts and studs without dulling quickly. This material choice determines the tool's ability to withstand the torque required for extraction on the listed bolt sizes. Buyers needing extractors for larger industrial fasteners beyond 1-3/8 in or for softer materials where a different alloy is specified should look elsewhere.