Dormer A170 HS 1/2in Parallel Shank Drill 16mm DOR1600 Standard helix, right hand spiral, 1/2in parallel shank drill, often referred to as a blacksmiths drill.General purpose drill, ideal for a wide range of materials where chuck holding capacity is limited.Suitable for both hand and machine use.WARNING:-For general purpose light-duty work only.Fracturing of the drill shank may occur if it is used for any other purpose or if extreme pressure is exerted on the drill.Size. 16mm DOR1600