35/64" X 3/16" Pilot Hole HSS Straight Shank Counterbore BoltsandNuts.com as well as 2-arbors and

as well as 2-arbors and 1-extra pilot drill

Part Number: 75C625WASS/316

Shape Cylindrical End-Cut Miniature

Part Number: BIT-DWDSPY

Spray on & Wipe off Tough Grease

35/64" X 3/16" Pilot Hole HSS Straight Shank Counterbore BoltsandNuts.com as well as 2-arbors andProduct Description Counterboring is the enlargement of a portion of a hole that has previously been formed. If the counterbored portion is shallow (1 8" or less), the operations is usually known as spot facing; for example, a flat seat for a bolt head or nut. If, on the other hand, the hole is enlarged to a considerable depth, it is designated as counterboring. These counterbores are made of two piece construction, having an integral shank and