"The cutting-tool in a screw-cutting machine; a screw-plate." -Whitney, 1911
A section of a screw-cutting die.
"A handle for holding the threaded die by which the thread is cut on a bar, a nut, or a pipe; a die-stock;…
"Jewelers' box of dies, stocks, and taps (called a screw-plate set." -Whitney, 1911