Uxcell Tap & Drill Bit Set, 1Pcs 1/2-13 Unc Straight Flute Thread Taps And 1Pcs

Descriptions: 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.