Extension Tap, Thread Size 3/8 In.-16, UNC, Overall Length 6 in, High Speed Steel, Bright (Uncoated), Right Hand, 16 The bright finish on these taps provides a smooth, polished surface. High-speed steel taps provide good wear resistance in general purpose tapping applications in a range of materials. Spiral-point taps have straight flutes with a spiral point that pushes chips in front of the tap as it moves into a hole and out the other side, eventually forcing the chips out of the hole. They are used for threading through holes.
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