Why can't the tap be nitrided? Drill bits are available.
Many imported taps are coated now. In addition to TiN, there are TiCN, TiAlN.
Tap can be treated by nitriding, often used in cast iron aluminum castings. The effect of nitriding is to increase hardness. Wearable ~!
Because the tap material is high speed steel, the cutting line speed is too low, coating cost performance is not high. So previous coatings were used less.
The surface of the drill seems to be a titanium nitride coating, not nitrided.
