Cyclone HSS Premium Grade Annular Cutter, 9 16 in dia x 2 in Depth, 3 4 in Weldon Shank, Includes Pilot Pin no checkout strain on neck muscles and strain on neck muscles and improves productivity Absorptive protection is engineered into the window Not surface coated so the window will not lose its protective qualities twisting and turning Turn screw to adjust pressure and fit Evolution standard geometry is sufficient for most drilling applications Manufactured specifically to maximize hole accuracy while minimizing cutter vibration and extending annular cutter life Using this standard geometry enhances accuracy and saves time This allows for a single ejection of slugs when drilling through stacked material