Woodruff keys, sometimes called Half-Moon Keys, are semicircular shaped keys, such that, when installed into a semi-circular pocket keyway in a shaft, they leave a protruding tab.. They are used to improve the concentricity of the shaft and the mating part, which is critical for high speed operation. They are called “keys” because they lock a component to the shaft by means of a corresponding keyway in a shaft.
Woodruff Keys Diameters
Woodruff Keys are available on the FCH Network with Imperial/US diameters that range from #3 to 5/8 and with Metric diameters that range from M1 to M14.
Woodruff Keys are available on the FCH Network in materials that range from Steel to Superalloy (Inconel, Hastelloy, Alloy 20)