Unique design, efficient, and widely used. 1) Sizes: HT-15, 19, 25, 32, 38, ... .3) Made of low carbon steel.4) Unique design, efficient, good quality, widely used . SizeToleranceL15MM~75MM-0.2MMb6MM(COMMON) AND 6.9MM(BIG HEAD ... )+/-0.2MMH1.5MM+/-0.1MMd2.2Mm-0.05MMd12.2MM+0.05MM HT Nail - Low Carbon 2.2MM ...