Rated at 90A durometer, this urethane backup ring is designed to prevent seal extrusion in hydraulic and pneumatic applications where pressure causes softer primary seals to deform into clearance gaps. The 90A hardness rating reflects a firm yet resilient urethane compound well-suited to dynamic and static sealing environments that demand consistent dimensional stability under load.
The Hercules Urethane Backup Ring 90A Durometer is manufactured by Hercules Sealing Products, a recognized supplier of sealing components for fluid power systems. Urethane construction offers strong resistance to abrasion, extrusion, and wear, making this ring a practical choice for cylinders, actuators, and other high-pressure assemblies where seal integrity is critical.
SKU: 575-443
Supplier Part Number (MPN): 575-443
Alternate Part Numbers: C1BV79, MI-01811040, MINO-00407Q30810
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Specifications
Alternate Part Numbers
Alternate Part NumberC1BV79, Alternate Part Number MI-01811040, Alternate Part Number MINO-00407Q30810
Brand
Hercules Sealing Products
Brand
Hercules Sealing Products
Pack Size
1.00
UOM
EA
Supplier Part Number
575-443
Product Weight
0.03 lbs
Product Questions & Answers (1)
Question by: Travis R on Mar 26, 2025, 6:46 PM
what exactly is a backup ring used for in a hydraulic setup, and does the urethane material hold up better than rubber in high-pressure situations?
Answer by: Customer Support on Mar 28, 2025, 7:51 AM
Backup rings sit behind a primary seal to keep it from extruding into the clearance gap under pressure. Urethane at 90A durometer is notably firmer than standard rubber compounds, which helps it resist that kind of deformation in demanding hydraulic applications. The Hercules 575-443 is built to that hardness spec, so it holds its shape where a softer material might start to flow or distort over time.
