How to choose the right o-ring

Many customers do not know how to choose the O-ring when purchasing it. The O-ring specification is mainly directly related to the material, size, tolerance and compression. Here's how to choose the right O-ring:

1. When selecting the o-ring specification, we should first determine the material of the o-ring. At present, in industrial parts, the materials of the o-ring in life include NBR nitrile rubber, NR natural rubber, CR chloroprene rubber, EPDM EPDM EPDM, HNBR hydrogenated nitrile rubber, SILICOME silicone, FKM, VITON, fluororubber, FLS silicone fluororubber, PU polyurethane, SBR styrene butadiene rubber, Buna butadiene rubber, acrylate rubber ACM, PTFE, PTFE, and so on. The above materials have different directions and uses, including oil resistance, chemical resistance, high and low temperature resistance, wear resistance, etc. Therefore, you must know where the product is used when selecting the O-ring specification, so that you can select the O-ring material you need.

2. The specifications and dimensions of O-ring are expressed in terms of outer diameter, inner diameter and wire diameter. The dimensions of inner diameter and wire diameter should be indicated on the engineering drawing. The outer diameter is equal to the inner diameter+2 * wire diameter. Or dimension the outer diameter and wire diameter.

3. The specification tolerance of O-ring mainly includes the tolerance of inner diameter and line diameter. The size tolerance of O-ring mainly depends on the size. The larger the size, the greater the tolerance of course. For example, the tolerance standard of O-ring with inner diameter of 0.05 to 1.79mm is+/-0.10MM, and the tolerance standard of O-ring with wire diameter of 0.05 to 1.79mm is+/-0.07MM.

4. The compression amount is very important when selecting the O-ring specification, because the selection is incorrect, and the product will not be sealed during assembly, which will not play the role required by the product. How to correctly select the compression amount of o-ring specifications? For reference, the compression amount of o-ring is generally determined by the hardness and material of o-ring. If the hardness of o-ring is 70 degrees, the compression amount of o-ring is equal to 20%. The lower the hardness of O-ring, the greater the compression of O-ring, which is mainly used in places with low pressure. The higher the hardness of the O-ring, the smaller the compression of the O-ring, which is mainly used in the environment with high pressure, pressure resistance and small resistance. By analogy, you can get the compression amount of any hardness O-ring you need.