O-rings play an important role in cap tightening, leakage and leakage prevention. 
For this purpose, there should be no burrs or flashes on the surface of the product and it must be processed to the precise dimensions from the mold making stage. 
In addition, dimensional errors must be strictly controlled during final inspection.

O-ring uses various materials such as EPDM, HNBR, and fluorine depending on the environment and price factors, but it generally requires excellent heat resistance, high heat resistance and chemical resistance.