No single physical property of rubbers is responsible for the successful performance of an oil seal or ‘O’ ring. The ultimate tensile strength, breaking elongation, modulus, shore hardness, creep and stress relaxation in tension and compression loads are all important physical properties that characterize a seal or ‘O’ ring. Compression strength and set together with stress relaxation or decay are important for effective sealing. The difference in these properties in a swollen seal is highly critical. An optimum swelling value in a fluid medium is a desirable feature. De-swelling decreases the seal pressure against the wall of the housing where the seal is fixed, leading to leakage. Over swelling minimizes the physical properties of the rubber. Seals made of polysulfide rubbers have extreme fuel resistance but undesirably high compression set. The effect of temperature on the seal is an important factor. Swelling under stress can increase at higher temperatures and a suitable compounding technique should be adopted to reduce this effect.
Many – too numerous to list, covering a vast range of designs, sizes, and materials suitable for a never-ending range of applications. Some designs conform to International Standards such as BS1399 and DIN 3760 for metric sizes and seal types, but the majority have been manufactured to suit particular applications – hence the enormous selection available. This blog is intended to assist in this selection and will consider seal type, materials, and sizes.

Step-by-step plan for correct installation
Above, are all the components of an oil seal and all its naming conventions. Beyond selecting the correct size, the three primary selection criteria are Material, Lip, and Case. If you have an oil seal you’d like custom designed and made, send us your specifications through our Oil Seal Design Form.
Standard 3760/3761
Silicone oil seals, which are also called VMQ, have strong resistance to temperature, which ranges from -140 degrees Fahrenheit to 392 degrees Fahrenheit. They are also resistant to ozone, light, and harsh weather conditions. Silicone is frequently used in hydraulics and pneumatics, as well as in the food and medical industries. Due to the material’s transparency and flexibility, it’s commonly chosen for the manufacturing of o-rings, molded parts, and flat seals, as well as electrical insulators.