SE JT3401DS Steel Dapping Block with 21 Round Cavities, 2.5" x 2.5" x 2.5" Block dimensions: 2.5" x 2.5" x 2.5" (21) round-shaped cavities Cavity sizes (mm): 4-14, 16, 18, 20, 22, 25, 30, 35, 40, 45, 50 High carbon steel Forms metal into a particular size or shape