ORING 568-357

Specifications

Actual I.D. 5.48 Inch	Actual O.D. 5.90 Inch	Actual Width 0.21 Inch	Alternate Part Numbers Alternate Part Number A-357, Alternate Part Number C1CF99, Alternate Part Number MI-08740555, Alternate Part Number MINO-00407X21602	Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	Nominal I.D. (in) 5-1/2	Nominal O.D. 5-7/8	Nominal Width 3/16	Supplier Part Number 568-357	Product Weight 0.03 lbs

Product Questions & Answers 3

Product Questions & Answers

trying to swap out an old seal, are these numbers the real size or just “nominal”?

Question by: Hubert H on Feb 28, 2026, 9:33 AM

Go by the actual dimensions: 5.48 inch inner diameter, 5.90 inch outer diameter, and 0.21 inch cross-section width. The nominal callouts (5-1/2 inch ID, 5-7/8 inch OD, 3/16 inch width) are the rounded sizing used for matching common industry seal sizes.

Answer by: Customer Support on Mar 2, 2026, 7:22 AM

Got an old cylinder seal that needs replacing, part number on it reads A-357. That the same as this one?

Question by: Johnny M on Oct 23, 2025, 10:20 AM

A-357 is one of the alternate part numbers tied to this exact o-ring, so you're looking at a direct match. The SKU here is 568-357, made by Hercules Sealing Products. Same seal, just cross-referenced under a different number. You should be good to go.

Answer by: Customer Support on Oct 24, 2025, 8:31 PM

Is this oring generally good for hydraulics, like for cylinders and stuff?

Question by: Jerry G on Jul 17, 2025, 4:00 PM

It is indeed suitable for both static and dynamic sealing tasks within hydraulic systems. This O-ring is designed for use in hydraulic cylinders, valves, and other fluid power assemblies.

Answer by: Customer Support on Jul 18, 2025, 5:53 PM