Woodruff Keys are used primarily for transmitting torque between a shaft and a hub. This page lists the industries and assemblies where they are specified, the selection criteria that matter for each application, installation practice, and the cases where a different fastener type is the correct choice. Parts are supplied to DIN 6888. Stocked across roughly M1 to M10, they cover general to heavy-duty work.
Typical Applications for Woodruff 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.
- Power transmission: locking pulleys, sprockets and couplings to a shaft.
- Gearboxes & motors: transmitting torque from a shaft to a hub.
How to Specify Woodruff Keys for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M1–M10; 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 DIN 6888. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Where Woodruff Keys Are Not the Right Choice
Not for very high reversing torque without an interference fit, and not as an axial retainer.

