Set of 3 - 6.5mm, 8mm and 10mm Removes spot welds in Boron and other hard sheet metals Set includes 6.5mm, 8mm and 10mm drill bit especially designed for spot weld drilling Made of ultra-hard solid tungsten carbide which prevents bit dulling from overheating Fast and easy way to remove most common size of spot welds in auto restoration and body repair work Bit has center nib to prevent walking.