Standards and sizes
SKF can supply O-rings in a wide range of sizes in accordance with various O-ring standards. Table 1 provides the most common national and international O-ring standards and their relevant sizes.
Inside diameter/cross section proportion
O-rings used in more demanding applications, such as those with higher operating pressures or larger misalignments, may require larger cross sections. SKF recommends inside diameter ID and cross section proportions as provided in diagram 1.
SKF supplies all O-rings with dimensional tolerances in accordance with ISO 3601-1:2012 Class B (table 2). They are suitable for any elastomer material provided that appropriate tooling is used, whereas the tooling most commonly used is based upon the shrinkage of nitrile rubber (NBR) with 70 shA hardness.
SKF supplies O-rings that all have surfaces in accordance with ISO 3601-3:2005 (table 3). This standard provides maximum acceptable imperfections and quality criteria for O-ring surfaces.