3/8"-1/4" HSS Threaded Shank Stop Countersink Shopify Collective a measure of strength verified

a measure of strength verified by a single-cycle test that applies torque until the specified value is reached without failure or permanent deformation

and Military Aeronautical Pipe Thread Specification

Part Number D/ARSD47/64

and small diameter pipes with these high-leverage pliers patterned after the power of a parrot's jaw

Part Number DWDA/CX12E

3/8"-1/4" HSS Threaded Shank Stop Countersink Shopify Collective a measure of strength verifiedProduct Description Countersink cutters may be used in all popular adjustable or micro stop countersinking units utilizing a 1 4 28 threaded shank drive. Made from the finest high speed tool steel. Precision ground to exacting tolerances and form relived to insure concentricity of 100 degree countersink angle. Brand Drill America Part Number TSC3 8 1 4 Size 3 8" 1 4" Material High Speed Steel Finish Uncoated (Bright) Body Diameter 3 8" Shank Type