Standard AS568 O-ring
AS568-251 O-Ring, 5.109 x 0.139 in (129.77 x 3.53 mm)
The AS568-251 O-ring (dash 251, also written 2-251) has an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), nominal 1/8 inch, and an outside diameter of 5.387 in (136.83 mm). We supply it in Buna-N (nitrile), Viton (FKM), EPDM or Silicone, in packs of 10, 25 and 100.
Size
| AS568 size | -251 |
|---|---|
| Inside diameter (ID) | 5.109 in (129.77 mm) |
| Cross section (CS) | 0.139 in (3.53 mm), nominal 1/8 in |
| Outside diameter (OD) | 5.387 in (136.83 mm) |
Rubber and pack prices
| Rubber | 10-pack | 25-pack | 100-pack |
|---|---|---|---|
| Buna-N (nitrile) 70AGood for water, air and petroleum oils; the usual choice for filter housings. | $5.99 | $11.99 | Request a quote |
| Viton (FKM) 75AGood for heat, fuels and many chemicals. | $18.99 | $50.99 | Request a quote |
| EPDM 70AGood for hot water, steam and chlorinated or chloraminated water. | $8.99 | $18.99 | $77.99 |
| Silicone 70A (orange)Good for a wide temperature range and food-contact use. | $8.99 | $19.99 | Request a quote |
A size match is not a fit claim for your equipment. Some sizes ship from stock; others have a 2-3 business day lead time before they ship. Not for oxygen, medical, aviation, scuba or other safety-critical use.