Retaining Rings

What are Retaining Rings?

Retaining rings (snap rings, circlips) are thin rings that sit in a machined groove on a shaft or inside a housing. The ring forms a shoulder that holds parts in place axially. Styles include internal, external, and E-style rings, along with matching installation pliers.

Internal vs. External Rings: which do I need?

Internal: fits a bore groove to retain parts inside a housing.
External: fits a shaft groove to retain parts on the outside of a shaft.
E-style (radial): slides on from the side where axial access is limited and provides a wide bearing shoulder.

How do I size a retaining ring?

Measure the nominal shaft diameter (external) or bore diameter (internal). That dimension is the ring size.
Verify the groove width and depth match the ring style. Use the ring’s datasheet groove dimensions as a cross-check.

E-style vs. snap ring: when to use each?

E-style: fast, side-loading installation, good when you cannot access the end of the shaft.
Snap ring (lug-hole type): best when you have axial access and want easy removal with pliers.

Materials and finishes

Carbon spring steel: high strength for general use.
Stainless 302/316: corrosion resistance, with 316 preferred in chloride or marine environments.
Other alloys: options like 17-7 PH and specialty alloys exist for high performance needs.
Finishes: oil dip, black oxide, zinc phosphate, and passivation are common.

Typical applications

Bearings, gears, pulleys, couplings
Equipment covers and flanged connections
Automotive, machinery, and MRO service

Installation & best practices

Confirm the correct style and size from the shaft or bore measurement.
Deburr the groove; align parts so the ring seats fully.
Use retaining ring pliers on lug-hole rings, compress/expand only as much as needed.
Seat the ring squarely in the groove and verify full engagement all around.

Troubleshooting & tips

Ring won’t seat: groove too shallow or burred; clean and verify dimensions.
Ring distorts during install: over-expansion/compression; use the proper pliers and minimal travel.
Corrosion in service: use stainless or select a protective finish appropriate to the environment.

Why buy Retaining Rings from AlbanyCountyFasteners.com

Internal, external, and E-style options with matching pliers
Carbon steel and stainless selections with practical finishes
Popular sizes for shafts and bores, ready to ship
USA-based support for sizing and installation questions

Retaining Rings FAQ

Short answers to help you size and install retaining rings correctly.

What size retaining ring do I need?

Measure the shaft for external rings or the bore for internal rings. Order by that nominal diameter and confirm the groove dimensions on the datasheet.

What’s the difference between internal and external rings?

Internal rings sit in a housing groove and resist inward force. External rings sit in a shaft groove and resist outward force.

When should I choose an E-style ring?

Use E-style when you need side installation or a wider shoulder on a shaft and you cannot access the end to slide a snap ring on.

Which material should I pick?

Use carbon spring steel for general duty, 302 stainless for broad corrosion resistance, and 316 stainless for chloride or marine exposure.

Can retaining rings be reused?

They can be removed, but repeated stretching or compression may reduce holding force. Inspect for distortion and replace if in doubt.

Do I need special pliers?

For lug-hole snap rings, use retaining ring pliers sized to the ring. Engage the holes and compress or expand only as needed to seat the ring.

How do I prevent failures in service?

Verify groove dimensions, choose the correct style and material, avoid over-expansion during install, and ensure the ring is fully seated all around.