Hardfacing is applied on gage surfaces of bit blades, the leading and trailing edges of bit blades, and on carbide inserts. The gage surfaces contains natural diamonds, synthetic diamonds, thermally stable polycrystalline (TSP) diamonds and carbide inserts, and the hardfacing is applied over at least a portion of them. As primary cutters on the bit blades are worn down during drilling, the gage surfaces of the bit blades are also worn down. A hardfacing is applied to the worn gage surfaces of the bit blades, thereby allowing the drill bit to drill deeper and longer without requiring replacement.