Metric Tap & Drill Bit Set: Tap thread size: M5 x 0.8 (right hand); twist drill bit size: 4.2mm (right hand). 6542 (M2) high speed steel tap and drill bit set offers excellent heat resistance and hardness for durability and longevity, and good cutting performance for clean, precise holes. Wide Applications: Thread tap and drill bit kit can create threads or re-thread or jammed threads. Straight flute tap is suitable for through holes or shallow blind holes. Used for cast iron, aluminum, stainless steel, carbon steel, aluminum alloy, bronze and hard plastics. Features: Thread Tap: Straight flute design, clear threads and no burrs, downward chip removal, fast and precise tapping. Machine tap is used in drill presses, tapping, CNC and milling machines. Not recommended for hand use and electric drill tapping. Twist Drill Bit: Spiral flute chip space design to remove chips quickly and cleanly. Provide neat and smooth cuts. Finish: Titanium coated drill bit has enhanced hardness, corrosion and rust resistance, heat resistance, and reduces friction for smoother and faster drilling. Uncoated thread tap is great for a wide range of applications. Use with tapping oil to get higher quality threads and more durable taps. Use an appropriate lubricant to reduce friction and heat build-up. Tips: Drill holes with a twist drill bit first, then tap with a thread tap. The tapping angle should be 90 degrees vertical and stable. The higher the hardness, the slower the speed. Fast speed with small torque; slow speed with high torque. The tapping depth should not exceed 1.5 times the diameter of the tap. Thread tap adopts straight flute design, with clear threads and no burrs. Screw tap provides downward chip removal, fast and precise tapping, suitable for through holes or shallow blind holes. Machine tap is used in drill presses, tapping, CNC and