Carter and Son Handles are designed specifically for the tools they make but can be used with other unhandled tools. The handles are made of solid 6061 Aircraft Aluminum. Each handle have a 3/4" hole. Adaptors are sold for adapting the handle to smaller hole sizes. The tools are held in place securely with two set screws. The set screws contact the flats milled on the tang of the tools to prevent unwanted rotation.