Round Hole Tool Steel Draw Plate B Reduce and shape the thickness of brass, copper, gold, silver, platinum or soft steel wire. Made of thick, high-grade tool steel, carefully stamped with style identifying letter and hole sizes. The holes are progressively smaller, in proper increments, so that wire drawn from a preceding hole will go through the next hole easily. Occasional annealing will keep wire soft, and bees wax can be used as a lubricant. Has 20 holes. Holes are round. Largest hole has 0.076" (1.9mm) diameter. Smallest hole has 0.018" (0.46mm) diameter.