Dormer A170 Series HSS Twist Drill Bit, 25mm Diameter, 159 mm Overall

Series of HSS plain stem drill bits of diameter 12.7 mm at a normal helix of 30° and sharpening of 118°.
These drill bits are for general piercing of steel, cast iron, etc.
The reduced stem of 12.7 mm allows work with machinery equipped with spindles with a maximal capacity of 13 mm (1//2").