Description of Union Butterfield Round Threading Stocks Cutting Tools for Threading Dies
Die Stocks. Designed for use with adjustable round split dies. The die is held securely by two opposed screws in the stock which locate in two indents in the die.
Cheap metal body and screws not designed for use with a Union Butterfield die. The countersinks on the UB die are 180 degrees apart, but this holder only has three 45 degree holes. I hate cheap Chinese instruments, but their matrix (like Enco's Interstate/MHC) is way better than this and 1/3. Price.
Pros
Designed for use with adjustable round slotted dies