The DF-1680TC Titanium Carbo Nitride (TiCN) coating on this bit will lower friction and keep the edge sharp longer than regular drill bits. The twist is 10mm and the shank is 8.0mm and has a flat spot on it to be tightened into our DF-15 Series Spot Weld Drills.
Our drill bits a specifically designed for the abuse of spot weld drilling. Flat ground for strength, centering nib to prevent walking. These German made spot weld bits are available in 2 sizes: 8.0 (DF-1680TC) and 10.0 mm (DF-1610TC). 8 mm or .314 inches.