5/16 X 3/8 X 3/4 X 2-1/2″ 4 Flute M42 Cobalt Fine-Pitch Roughing End Mill ~ Cutting diameter is 5/16″. ~ Shank diameter is 3/8″. ~ Cutting length is 3/4″. ~ Overall length is 2-1/2″. ~ Ground From Solid M42 Blank. ~ 8% cobalt. ~ Center cutting. ~ Low co-efficient friction. ~ The pressure of the cut is distributed over many teeth. ~ Recommended for high production milling in difficult-to-machine materials such as inconel, hasteloy, titanium alloys and other materials up to RC 40.