1/4"-20 UNC, 0.515" L, Cadmium Plated, Steel, Knurled, Open End, Threaded Insert Threaded Insert Type Knurled, Open End Nominal Diameter 1/4 in TPI 20 Thread Series UNC Drill Size 0.4 mm Overall Length 0.515 in Material C1010/C1110/C1215 Steel Finish...