It is long-lasting without requiring maintenance under heavy conditions, it should protect the motion bearings, however, it should not leak out the oil and grease required for the lubrication and cooling of the bearings. For this reason, the importance and need of oil seals with steel cheeks is increasing. Şahin L / T (Loftym) seal group is made of two wear resistant alloy steels. 60 HRC hardened and their foreheads are ground. It was lapped and ultrasonically cleaned and mounted on steel. This serves as a sealing. It changes depending on the temperature of L / T felt groups. At operating temperatures between 40 and 120 ° C, nitrile rubber, 60 to 180 ° C silicone rubber and 30 to 250 ° C viton rubber are used. The most important factor affecting the L / T felt is the loss of the properties of the steel surfaces. However, when the rubber group stays in oil too much, it loses its flexibility and impermeability. When the seals are opened during repair and overhaul, new seal sets are used instead of the old ones.