Jeweler's tool set for making internal and external threads on small jewelry parts. 14 matching tap and die from 0.7mm to 2.0mm in 0.1mm increments. Internal-thread cutting taps, 3/32" shank; use with pin vise or other hand tool. Screw-plate for threading wire or making your own screws. Hardened and tempered carbon steel; cuts gold, silver, brass, copper, soft steel and maintains edge