7/8" X 5/16" Pilots for Counterbore Quantity:1 Part Number: EZ-EK21115

Part Number: EZ-EK21115

Part Number: 87C450HSBA325PL/PT

Part Number DEW112320

Part Number DEWCSK5/8-90

200x - 50CPTNCZ - 1/2"-13 Grade 8 Hex Prevailing Torque Top Lock Nuts Zinc

7/8" X 5/16" Pilots for Counterbore Quantity:1 Part Number: EZ-EK21115Product 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