Common materials of construction include high-speed steel, cobalt, carbide, and diamond PCD. Drill bits may be coated to assist in cutting lubricity and/or add abrasion resistance for longer tool life ...

Moly drill bits work well with mild steel. Cobalt bits are expensive and best choice for the abuse common in farm shops, but…drill bits by definition are “consumable items.” The differences ...

whereas cobalt is typically used for harder materials like cast iron or stainless steel. Tungsten-carbide tipped (TCT) and ...