O-rings are made using a standard or custom size groove mounted Spira gaskets. O-rings can be used either in circular or rectangular groove applications. We assemble the o-rings either by winding one end of the spiral into the other and soldering (Spira-Shield and Quick-Shield) or using adhesive (Endur-o-Shield, Flexi-Shield and D Multi-Seal). When installing a D Multi-Seal o-ring into a rectangular groove, put the corners in first, then press the gasket into the straight sections of the groove. We recommend a corner radius of 1 12 times the diameter of the spiral or width of the D Multi-Seal gasket.