?Correct selection of o-rings specification mainly with material, size, tolerance, has important direct relationship between the amount of compression. The following is my experience for everybody to share:

??1, when choosing o-rings specifications must first determine the material of good o-rings, currently in industrial components, in the life of o-rings material NBR NBR, NR, natural rubber, CR rubber, EPDM EPDM, HNBR hydrogenated nitrile rubber, SILICOME silica gel, FKM, VITON, fluorine rubber, FLS silicon fluorine rubber, PU PU, SBR styrene-butadiene rubber, Buna Buna, acrylate rubber (ACM, PTFE, PTFE and so on. Above materials each have each destination and purpose, oil resistant, resistant to chemicals, with high and low temperature resistance, abrasion resistance and so on. So when choosing o-rings specifications must want to know where the product use, what needs to be resistant to, work, life, in this way can we have the choice of target o-rings materials you need.

??2, o-rings size with outside diameter, inside diameter, wire diameter to express. On our engineering drawing as long as indicate the diameter and the size of the wire diameter, outside diameter is equal to the inner diameter + 2 * wire diameter. Or only indicate outer diameter and the size of the wire diameter. The two optional one.

??3, o-rings specification tolerance mainly include tolerance of inner diameter, wire diameter tolerance. O-rings specification tolerance mainly depends on the size of the size, the greater the size, the greater the tolerance of course. Such as the inner diameter of 0.05 to 1.79 mm o-rings tolerance is + / - 0.10 mm, 0.05 to 1.79 mm wire diameter of o-rings tolerance is + / - 0.07 mm.

??4, choosing o-rings specifications compression capacity is very important, because the selection is not correct, when the product assembly or not seal, or when the assembly is too tight, so no have the effect of product needed. That we how to choose the right o-rings specifications of the amount of compression, the following to do for you reference: o-rings amount of compression is mainly determined by the materials and the hardness of o-rings, if the hardness of o-rings is 70 degrees, so the compression of o-rings amount equal to 20%. That, of course, the lower the hardness of o-rings, the greater the amount of compression of o-rings, mainly used in the place of low pressure. So the higher the hardness of o-rings, the less the amount of compression o-rings, mainly used in high pressure, high voltage, small resistance of the environment. By analogy, you can get what you need any amount of compression hardness of o-rings.