The ISO flange system provides a variety of fasteners. Small ISO-QF flanges (QF10-QF50) have six (6) styles of quick clamps: wing nut, ratchet, chain, CNC aluminum (T-nut), CNC aluminum toggle, and CNC stainless steel (hex nut). Large ISO-QF flanges (QF63-QF500) use band clamps for sealing. ISO-LF flanges are fastened with single or double claw clamps. ISO-LFB flanges are fastened with bolts. In addition, there a several special purpose flanges. Bulkhead clamps are used to to fasten ISO-QF style flanges directly to chamber walls, bulkheads, baseplates, collars, or valves. Rotatable bolt rings and retaining rings are used to convert ISO-LF (claw clamp) style flanges to ISO-LFB (bolted) style flanges. Adaptive bolt rings are used to convert ISO-QF style flanges to either ISO-LF or ISO-LFB style flanges.