7/8" X 1/4" Pilot Hole HSS Taper Shank Counterbore Quantity:1 The BoltsandNuts

The BoltsandNuts

Part Number CTC5-530-905

Part Number CTC5-530-281

Tap Drill Size 3-1/4"

Part Number: DUR-JSCSL-306040-94T-D720

7/8" X 1/4" Pilot Hole HSS Taper Shank Counterbore Quantity:1 The BoltsandNutsProduct 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