HIGH STRENGTH STEEL SCREWS AND BOLTS, AND METHOD OF PRODUCTION

摘要

1. Screws, bolts, nuts and other components of steel with high mechanical characteristics which are produced by cold or warm die forging from rolled bar or wire characterised in that they are of the following composition in percent by weight : 0.060 to 0120 ; Si 0.30 to 0.70 ; Mn 1.30 to 2.00 ; Nb 0.050 to 0.100 ; B 0.0025 to 0.0060 ; Al 0.040 to 0.080 ; N =< 0.010 ; the usual impurities among which the total of the metallic impurities such as Ni, Cr, Cu and Mo does not exceed 1.0 ; and the balance Fe.