An O-ring is a donut, or torus shaped seal typically used to prevent the passing of air or fluid. In other words, O-rings are used to keep fluid or air IN or OUT of a defined space.

Basically an O-ring is used to block a pathway that fluid or air may escape through. O-rings are usually put into a groove to hold them in place and then squeezed between two surfaces.

When you squeeze the O-ring between two surfaces you are taking up the clearance and blocking the pathway that the fluid or air wants to escape through.

O-rings are sized by the inside diameter (I.D.) then by the cross section (C/S) or width (W).

The Different Materials Used For Making O-Rings :

• NBR (BUNA-N , Nitrile)
• EPDM
• Neoprene
• Silicone
• Fluorosilicone (FVMQ)
• Viton (FKM) – (AED & GLT Grades)
• AFLAS
• High Nitrile
• HNBR
• FFKM