DIN 8378-2006《攻丝前先钻孔用直柄阶梯麻花钻》
This standard applies to Subland Twist Drills with Parallel Shank intended for use in the manufacture of holes prior to Tapping Screw Threads - series medium - according to DIN 336, producing simultaneously Relief Countersinks according to DIN EN 20273.#,,#