Screw and bolt extractors are made from high carbon steel.
The properties of carbon steel depend on the amount of carbon it contains. You can find 3 types of carbon steel: low, medium and high:
Low carbon steel – Contains up to 0.3% carbon. This improves ductility but has no effect on strength. Ductility is a measure of how much stress a material can take before it fractures.
Medium carbon steel – Contains between 0.3 to 0.5% carbon. This is ideal for machining or forging and where surface hardness is desirable.
High carbon steel – Contains more than 0.5% carbon. This becomes very hard and will withstand high shear and wear.
Hardened steel
Screw extractors are also available in hardened steel, which is the term used for a medium or high carbon steel that has been given special heat treatments.
When choosing an extractor, hardened steel would be the best material, as it is stronger than standard high carbon steel because of its heat treatments.
High carbon steel is often the main material used to make bolt grips.