11/16" X 3/16" HSS Aircraft Counterbore 1/4" Shank Quantity:1 Drill Size: 27/64"

Drill Size: 27/64"

Part Number DWRRHD15/16

Part Number: 75F550HCS8Y/USA

Diameters: 3/8"-16

Part Number: M16C50SSSAFLAT45HBO

11/16" X 3/16" HSS Aircraft Counterbore 1/4" Shank Quantity:1 Drill Size: 27/64"Product 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