1 Grinding Lathe Cutting Tools Session 8

2 Grinding Lathe Tool Wide variety of cutting tools for lathe All have certain angles and clearances regardless of shape Shape and Dimensions of General-purpose Lathe Toolbit

3 Grinding a Lathe Toolbit 1.Dress face of grinding wheel

4 Grinding a Lathe Toolbit 2.Grip toolbit firmly, supporting hands on grinder toolrest 3.Hold toolbit at proper angel to grind cutting edge angle Tilt bottom of toolbit toward wheel and grind 10º side relief or clearance angle

5 10º side relief or clearance angle Grinding a Lathe Toolbit Cutting edge ~ ½ In long and extend over ¼ width of toolbit

6 4.While grinding, move toolbit back and forth across face of wheel Prevents grooving wheel 5.Toolbit must be cooled frequently during grinding Never overheat toolbit! Quench often! Never grind HSS with Silicon Carbide wheel Grinding a Lathe Toolbit

7 6.Grind end cutting edge so it forms angle of 70-80º with side cutting edge Hold tool so that end cutting edge angle and end relief angle of 15º ground at same time Grinding a Lathe Toolbit

8 7.Using toolbit grinding gage, check amount of end relief when toolbit is in toolholder Grinding a Lathe Toolbit

9 8.Hold top of toolbit approximately 45º to axis of wheel and grind side rake to approximately 14º Do not grind below top of toolbit Side rake ground the length of the cutting edge Grinding a Lathe Toolbit

10 9.Grind slight radius on point of cutting tool, being sure to maintain same front and side clearance angle 10.With oilstone, hone cutting edge of toolbit slightly Lengthen life of toolbit Enable it to produce better surface finish on workpiece Grinding a Lathe Toolbit