To address this challenge, many companies have turned to advanced materials and innovative designs. For example, some seals are made from high-performance elastomers that can resist heat, cold, and chemicals better than traditional rubber compounds. Others feature intricate labyrinth patterns or multiple layers of protection to reduce the risk of leakage and wear.

Seals are classified by O.D. wall material, lip type, and whether they have a spring or not.
Major oil seals are specified in ISO 6194-1 and JIS B 2402-1.
Table 2 shows the common types of oil seals, while Table 3 shows the features of each type of oil seal.
Table 4 lists the JTEKT oil seal type codes and corresponding ISO and JIS standards.