Quartz Cones, Sockets and Cup & Ball Joints All our joints have the following advantages Bevelled edges for greater chip resistance. Exclusive extra heavy rim on all outer joints for greater impact resistance. Standard taper joints comply with the ASTM specifications E676. All standard taper joints are ground to a 10:1 taper. Large stock levels held. Non-standard taper joints and longer lengths are available for quotation upon request. please contact me chinamerry315 AT hotmail DOC com