METHOD FOR MAKING WHEEL NUT Russian patent published in 2004 - IPC

FIELD: plastic metal working, namely manufacture of wheel nuts, mainly for passenger automobiles. SUBSTANCE: method comprises steps of cutting off blank with diameter consisting 1.08 ÷ 1.12 of diameter of ready nut; upsetting blank while making preliminary recess in one end of blank for forming inner chamfer and preliminarily forming cone in its other end for making outer chamfer; finally forming recesses at both ends and simultaneously shaping outer working cone surface. Small diameter of preliminarily formed cone consists 0.95 ÷ 0.98 of small diameter of ready nut. Then preliminary operation of forming outer working cone surface is going on and simultaneously pressing out of preliminary opening for cutting thread is formed by depth consisting 0.8 ÷ 0.9 of height from end of blank until outer cone working surface. Polyhedron of nut is formed by reduction during one operation in last but one shaping position while keeping pressed out opening for cutting thread at making flange and inner chamfers on both ends. Opening is punched at basing according to outer working cone surface. EFFECT: enhanced quality of wheel nuts, increased strength of tool. 1 dwg