ASME B107.15 pdf download FLAT TIP SCREWDRIVERS 5.4.2 Finish. The blade shall be treated in a manner to resist rust or corrosion. There shall be no evidence of peeling or chipping of any coating where applicable. 5.4.3 Hardness. The tip portion of the screwdrivers or the entire blade shall be hardened to not less than 48 HRC (para. 6.2). 5.4.4...