9/16" X 1/8" HSS Aircraft Counterbore 1/4" Shank Quantity:1 The smaller flat end keys

The smaller flat end keys are made from 8660 nickel chromium molybdenum steel that's heat-treated to 54–58 HRC and the larger flat end keys are made from 6150 chromium vanadium steel that's heat-treated to 44–50 HRC

and 3/4 inch drive adapters and 3/8

Part Number GLBCOX1251

The Tekton 134-Piece 4 mm and 1/4 Inch Multi-Bit Driver Set includes a 97-piece 4 mm bit set and a 37-piece 1/4 inch bit set

Height: 17-13/16"

9/16" X 1/8" HSS Aircraft Counterbore 1/4" Shank Quantity:1 The smaller flat end keysProduct 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