... polished. These dapping blocks mirror polished are used with punches to make hemispheres. Six working surfaces with 21 various sized depressions ... .It features 17 machined half-sphere depressions: 3.2, 4.8, 6.4, 7.9, 11.1, 12.7, 14.3 ... .1, 20.6, 22.2, 25.4, 28.6, 31.8, and 34.9mm(1/8” to 1-1/3”). Jewelry Tool Steel Dapping ...