Forged steel and built to withstand the daily repeated usage of professionals working with the heaviest full grain leather to the softest calfskin. The cutting tubes (sized 5/64, 3/32, 7/64, 1/8, 5/32 and 3/16”) are carbon steel, quite sharp, and especially hardened for longevity. A replaceable copper anvil further preserves the cutters. The 1-1/2” deep throat allows you to reach well in from the edge of your work piece and the entire tool is polished smooth for safe, snag-free contact with your work. This is hands-down the best tool of its kind available.