DentFix 1667 6.7mm Tungsten Carbide STC for Usibor- 6.7mm x 80mm drill bit by Dent Fix Equipment is made of tungsten carbide and is designed to penetrate ultra high strength metal panels of Boron and Usibor steel. These metals are usually used in structurally significant areas such as intrusion beams, rocker rails or A- and B-door-pillars. The triple fluted bit is designed to spread torque over a greater surface area and a specialized coating is applied to the bit for friction-free usage. This bit is specifically useful on Mercedes Benz rockers to create holes for riveting on the CL Class.