1-1/2" X 3/8" Pilot Hole HSS Straight Shank Counterbore Quantity:1 Drill Size: 25/64"

Drill Size: 25/64"

Part Number MMO3/16-4FSE-LONG

Size 1-19/64"

Shape: Inverted Cone Double Cut

Part Number DWTSR1-51632

1-1/2" X 3/8" Pilot Hole HSS Straight Shank Counterbore Quantity:1 Drill Size: 25/64"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