One important lesson for woodturners to learn is not to use the chuck key for removing the chuck from the headstock; doing this can damage the hole in the chuck as well as risk breaking the key. This C spanner has been specially produced for the 100mm Clubman, Goliath and previous model Woodturner's range of chucks. This should be classed as essential equipment for all users of these chucks. Also suitable for SK80 chucks.