ERIKS type M (type B according to the DIN standard) has a single metal casing and rubber sealing lip. Since the casing is made of metal, it must be fitted in a well-finished, undamaged groove. Large volumes of oil seals with metal casings are often cheaper, which is why they are often used as original equipment in machines. However, if an oil seal has to be replaced, types with a rubber exterior (type R or RST) are easier to fit. Type MST is similar to M and commonly used. The difference is the dust lip in the MST oil seal that prevents dust and dirt reaching the sealing lip, and extends its service life in dusty environments.
What are Oil Seals? 6 Things DIYers Should Know
Oil seals can show good sealing performance in combination with properly designed shafts and housings.
PTFE, which is used in the well-known brand Teflon®, is less commonly used, but it is the preferred material for specific rotating seals in the chemical, food and pharmaceutical industries. This material is notable for having a very low frictional resistance and the best chemical resistance. It can also withstand a very wide range of temperatures in these types of seals; -80 ˚C to 200 ˚C. The shafts on which oil seals with PTFE lips are used require a harder and finer finish. Something like an axle sleeve can also be used to meet this requirement.

Car iridium spark plugs are a popular choice for modern vehicles due to their durability, high melting point, and superior conductivity. Iridium spark plugs offer enhanced performance and longevity compared to traditional copper or platinum plugs. The use of iridium in the electrode design allows for a smaller center electrode, promoting more efficient combustion and improved engine performance. Car iridium spark plugs are known for their ability to maintain optimal engine performance over an extended service life.