Feature●Recommended for use when there is sufficient room on a blind hole and tapping to the bottom is not required●General-purpose tap with 3-5 chamfered threads●Heat-treated carbon steel provides long life and clean, accurate threads●Rolled threads provide more accuracy than machined threads●Black oxide coating provides corrosion resistanceDescription Bosch black oxide taps and dies offer superior durability and speed for most general-purpose applications. Laser-etched marking ensures size identification and wont wear off. Ideal for cutting thread holes into metal and work equally well in plastic drilling applications.