Standard AS568 O-ring

AS568-390 O-Ring, 20.955 x 0.210 in (532.26 x 5.33 mm)

The AS568-390 O-ring (dash 390, also written 2-390) has an inside diameter of 20.955 in (532.26 mm), a cross section of 0.210 in (5.33 mm), nominal 3/16 inch, and an outside diameter of 21.375 in (542.92 mm). We supply it in Buna-N (nitrile), Viton (FKM) or Silicone, in packs of 10, 25 and 100.

Size

AS568 size-390
Inside diameter (ID)20.955 in (532.26 mm)
Cross section (CS)0.210 in (5.33 mm), nominal 3/16 in
Outside diameter (OD)21.375 in (542.92 mm)

Rubber and pack prices

Rubber10-pack25-pack100-pack
Buna-N (nitrile) 70AGood for water, air and petroleum oils; the usual choice for filter housings.Request a quoteRequest a quoteRequest a quote
Viton (FKM) 75AGood for heat, fuels and many chemicals.Request a quoteRequest a quoteRequest a quote
Silicone 70A (orange)Good for a wide temperature range and food-contact use.Request a quoteRequest a quoteRequest 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.

Not sure of your size?Measure the inside diameter and the thickness of your old O-ring, or send us the part number, and we will match it.Contact usSearch sizes in the Filter Finder