The boa bolt remover kit is made of high quality hardened steel fits all standard variable speed drills removes heavy duty bolts quickly and safely winslow tip removes bolt tips broken below the surface suitable for use in industrial engineering automotive aeronautical and motorcycles bolt sizes 6 12mm 14 12in removes screws 6 10 12 14 bolts 5 14mm fasteners 2 8 grade hardness 56 109