Tapered bores for keyed hubs shall have a minimum of 70% transfer of bluing (surface contact) to the taper gage.
键槽轮毂的锥孔应至少有70%的着色（表面接触）转移到锥度计上？
2
In this paper, a mathematic relationship between space position of gagesurface and bit size, and other design parameters is derived on the basis of geometry of cone bit.