SECTION 5.5

When face sharpening broaches of any type, a 60-80k vitrified bond grinding wheel is commonly used. After sharpening, a polishing wheel (100-210k) is used to blend the back radius with the face angle radius and supply the chip being cut with a smooth surface on which to slide. A recommended grinding speed in face sharpening is 5,000-6,000 surface feet per minute (SFPM). This allows a good cutting action between the grinding wheel and the broach tool.

When sharpening a surface or flat broach, the wheel is traversed laterally across the cutting edge of the tool. The angle of the grinding head should be tilted the same as the face angle on the tool and remove about 0.005" to 0.010" stock from the tool face.

Slab broaches can more readily be top ground to eliminate worn corners and then face sharpened and polished. With slab broaches, shims may be used to bring the broach tool back to the proper set-up dimension.