The Sinclair Cross Bolt Die Lock Rings are machined from stainless steel and fit all standard 7/8-14 reloading dies or press mounted accessories. The lock ring surfaces are machined flat and parallel, and the cross bolt design with no lock screw contacting the die threads is preferred by most experienced reloaders. We incorpated a larger hex screw crossbolt (7/64" Hex) but designed the crossbolt recess so the hex head does not protrude from the lock ring circumferenced. Will work with the Forster CO-AX Press.