A General Guide to Particle Sizes:

A General "Rule of Thumb" regarding which type of coating to use, CBN or Diamond is that Diamond is mainly used on any nonferrous materials, such as: carbides, ceramics, glass, fiberglass, reinforced plastics etc., and CBN is for use on ferrous materials, tool and diesteels, high alloy steels and nickel rich alloys.

For optimum results, you may use the following general grinding guideline with both Diamond and CBN tools:

TYPE OF OPERATION:                   GRIT SIZE:

• Heavy Stock Removal                                    60/80 Grit

• General Grinding                                            80/100 Grit

• Semifinish Grinding                                       100/120 Grit

• Finish Grinding                                               140/170 Grit

• Fine Finish Grinding                                       200/230 Grit

Grinding Speed Conversions:

To find SFPM at known grinding RPM: SFPM = (RPM) (p ) (D)/12

To find required RPM: RPM= (SFPM) (12) (p ) (12)/(p ) (D)

SFPM = Surface Feet Per Minute

D = Diameter of Wheel

RPM = Revolutions Per Minute

To convert M/S to SFPM : SFPM = (M/S) (197)

To convert SFPM to meters per second (M/S) : (M/S) = (SFPM) (.005)

To convert inches (in) to millimeters (mm) : mm = (in) (25.4)

To convert millimeters (mm) to inches (in) : in = (mm) (.0394)