Masonry drill bit set these masonry drill bit set are a set of 5 drill bits varying in size from a 4mm to a 10mm these drill bits have been coated in chrome for a extra durable design the cutting tip is made from tungsten carbide bonded to a spiralled steel shaft to make sure it gets through the brick block stone and concrete drill bits masonry drill design sizes 4 5 6 8 10 mm chrome plated rolson warranty 5pc