Olympic Bars All Olympic style bars are U.S. made with one-piece welded ends. Self-lubricating bushings allow ends to rotate smoothly. Precision knurl makes a positive grip and a locking shoulder bolt holds ends securely. Seven foot power bar Heat treated quench and tempered turned ground and polished high strength steel. 165k min yield strength. Black oxide or Chrome, center knurl available. Five Foot Olympic Style Bar Ground and polished steel, black oxide. Five Foot Olympic Style EZ Curl Bar Ground and polished steel, black oxide.