Hex Keys (Allen Keys) are used primarily for a range of mechanical fastening duties. This page summarizes where they fit, the industries that rely on them, and the practical points to get right when you specify them — to ISO 2936. Stocked across roughly M0.7 to M60, they cover general to heavy-duty work.
Typical Applications for Hex Keys (Allen Keys)
The most common settings where these are specified:
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
- Fabrication & metalwork: bench and on-site assembly of steel frames, enclosures and weldments.
How to Specify Hex Keys (Allen Keys) for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M0.7–M60; check the full table below for the exact dimensions of each size.
- Material: Choose the material and finish for the service environment — plated steel for general use, stainless for corrosion resistance.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to ISO 2936. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Where Hex Keys (Allen Keys) Are Not the Right Choice
Match the fastener to the load, environment and whether the joint must be reopened; the wrong class or style is the usual cause of joint failure.