Mechanical Designs » Resources


Keys and Keyways

The size of key for a particular shaft should be as per the BS standard and can be seen here: Standard Keyway Sizes.

Small keys are often square in section and the larger ones rectangular. A slot drill can be used to mill the keyway in shafts of any size, the female side is more difficult (you’re not surprised) bore sizes of up to 30mm can be cut with a broach but larger keys need to be cut with a slotting machine.

Taper Lock Bush


Where possible it is a good idea to use a Taper lock bush to transmit the drive. It clamps the shaft, is easily replaceable and gives flexibility on the shaft size.


To avoid using a key all together there is the option of keyless bushing, like this:

Keyless Bushing - small

for small shafts and like this:

Keyless Bushing - large

for larger shafts. These are a great option if you can set them up ensuring the face runs true and also there needs to be enough wall thickness to take the high bursting force they generate.

For help with power transmission call 0422 218 241 or mail