15/16" X 1/4" Pilot Hole HSS Straight Shank Counterbore BoltsandNuts.com L-key sizes are marked in

L-key sizes are marked in two ways: both with a high-visibility laser marking and a stamped marking

Diameter/Pitch: 5/16"-18

Flute Length 106

Part Number: 50C700WASS/316

Part Number: 75X450DPAPL

15/16" X 1/4" Pilot Hole HSS Straight Shank Counterbore BoltsandNuts.com L-key sizes are marked inProduct 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