Metal rings such as: RTJ, BX, oval, circle, triangle, lens etc. METAL RING GASKETS SPETORING® SPETORING® R-BZ Calculation factors, characteristic data. SPETORING® RTJ-OR oval soft iron Calculation factors, characteristic data. Comments SPETORING® RTJ-OR oval 321 Calculation factors, characteristic data. Comments SPETORING® RTJ-R octagonal SA-182 F5 Calculation factors, characteristic data. SPETORING® LENS 2696 SA-182 F321 Calculation factors, characteristic data. SPETORING® LENS 2696 SA-182 F5 Calculation factors, characteristic data. SPETORING® LENS 2696 soft iron Calculation factors, characteristic data.