Tech Talk
What is a "Woodruff Keyseat Cutter"?
The Woodruff keyseat cutter is designed primarily to mill keyseats in shafts. Accordingly, the teeth are concentrated in a narrow "face" at the end of the tool. Keyseat cutters can have as many as 16 teeth, depending on the diameter of the tool. They keyseat cutter has a standard 1/2 inch diameter straight shank or maching #404 taper shank which tapers to a smaller size where it joins the face to prevent workpiece interference.
Keyseat cutters come in 41 standard sizes, each designed to produce a slot for a specific American National Standard key number. The cutters are identified according to the keyseat number they produce; thus, a No. 808 cutter will produce an ANS NO. 808 keyway. The faces of the keyseat cutters range from 1/4 inch diameter by 1/16 inch wide for the smallest No. 202 standard keyway, to 1-1/3 inch diameter by 3/8 inch wide for the largest No. 1212 standard keyway.
Keyseat cutters come in straight- and staggered-tooth styles. The staggared-tooth cutter has teeth with alternating right and left hand helix which provides a free cutting action. On both styles, clearance is ground into the sides of the teeth to prevent the tool from binding in the cut.