The grinding precision of high-speed steel tap teeth—particularly the radius (R) at the root of the flute—is critical to the quality of the tap.

This necessitates that the tip of the CBN grinding wheel be dressable to a very sharp point and retain that sharpness for as long as possible.

We have compiled the dressing parameters as follows:

Equipment：Heyi‑da Special Tap‑tooth Grinding Machine

Dressing Wheel：1A1  180×31.75×10, Green Silicon Carbide F150K

CBN Grinding Wheel：14E1 400×203×15×5×60°, B46, C100

Dressing Parameters：

CBN wheel speed: 100 RPM; Green silicon carbide dressing wheel speed: 700 RPM; feed rate: 80; dressing infeed per left‑right stroke: 0.01 mm.

The required dressing cycles depend on the initial run‑out of the CBN wheel, mounting error, and whether the wheel bond formulation allows sharp‑edge dressing. Dressing time is approx. 1‑5 hours.