A.2863r/min B.1863r/min C.863r/min D.8263r/min
A.0.6-0.8mm B.0.7--0.9mm C.0.8-1.0rnm D.0.9-1.1mm
A.0.7~1.0mm B.0.8~1.1mm C.0.9~1.2mm D.1.0~1.3mm