Spiral rings vs circlips: which retaining ring is right for your application?

(See Rotor Clip at MachineBuilding.Live, 14 October 2026, on stand 114)

When selecting a retaining ring for your application, size alone does not determine performance. Ring geometry, installation method, and load distribution within the groove all influence how a ring behaves in your assembly.

For example, spiral retaining rings and tapered section rings (circlips) both secure components within a groove, but they achieve retention in fundamentally different ways. Spiral rings rely on a continuous coiled geometry that engages the groove uniformly around the circumference. Circlips use a stamped, lug-based design that compresses into position and locks into place through defined contact points.

What is a spiral retaining ring?

Spiral retaining rings are formed from a continuous length of flat wire that is coiled into a multi-turn or single-turn spiral profile. This creates a continuous ring geometry without lugs or defined end points. Unlike stamped retaining ring designs, spiral rings engage the groove through continuous contact around the circumference, creating a uniform interface between the ring and the housing or shaft. This geometry supports even load distribution around the groove once installed and helps minimize localised stress concentrations.

The lug-free profile of a spiral ring eliminates protrusions that may interfere with surrounding components, making them well suited for assemblies with limited clearance requirements. In multi-turn configurations, spiral rings provide 360 degree groove contact for consistent engagement around the assembly. They are available in internal and external designs and can be manufactured in materials including stainless steels, Inconel, and Elgiloy to meet application requirements.

Rotor Clip spiral rings also offer customisation flexibility in diameter and number of turns. The coiling process allows for efficient production with minimal material scrap, providing a cost-effective solution for a wide range of applications.

Spiral ring installation

Spiral retaining rings are installed by guiding the leading end into the groove and progressively winding the ring into place until fully seated. Unlike circlips, spiral rings do not require pliers or dedicated installation tooling, although simple tooling can be used for high-speed automated assembly. Once installed, the ring maintains continuous contact around the groove circumference. For removal, the ring's removal notch or scallop allows a screwdriver to be used to wind the ring out of the groove.

Common applications for spiral rings

Spiral retaining rings are commonly used in assemblies such as rotary unions, quick connect fittings, valves, couplings, and precision equipment in space-constrained or high-performance environments. Typical application characteristics include:

• Tight radial or axial clearance requirements
• Assemblies where lug interference cannot be tolerated
• Need for uniform load distribution around the groove
• Designs requiring a smooth, continuous ring profile within the assembly

Note: If clearance constraints or lug interference are a concern, a spiral ring is typically the preferred choice.

What is a circlip?

Tapered section retaining rings, commonly referred to as circlips, are widely used retaining ring designs valued for their strength and versatility. The ring features a tapered cross-section, where the radial wall height gradually decreases from the top of the ring toward the free ends and lugs.

This geometry promotes even stress distribution and supports strong axial load capability. As a result, the ring maintains secure engagement within the groove and can withstand significant thrust loads across a wide range of assemblies.

Unlike spiral retaining rings, circlips use an open ring design with integrated lugs and lug holes, allowing them to be installed and removed using standard retaining ring pliers, applicators, or automated assembly equipment. Their near full circular contact within the groove provides consistent engagement for applications requiring dependable axial retention.

Circlip installation

Circlips are installed using retaining ring pliers or automated assembly equipment that compress the ring's lugs, allowing it to enter the groove. Once released, the ring expands and seats securely within the groove. This installation method supports repeatable, tool-based assembly in high-volume production environments. For removal, the same compression process is used to disengage the ring for service or replacement.

Common applications for circlips

Tapered section retaining rings, or circlips, are commonly used in assemblies such as gearboxes, bearings, transmissions, and hydraulic systems where controlled axial retention and efficient assembly are required. Typical application characteristics include:

• High thrust load retention requirements
• Standardised assemblies designed for pliers or automated installation
• High-volume production environments
• Fast, repeatable installation cycles

Note: If thrust load capacity and installation speed are priorities, a circlip is typically the preferred choice.

Selecting between a spiral retaining ring and a tapered section ring (circlip) is typically driven by how the assembly manages space, load and installation. Each design uses a different retention approach, which directly affects groove engagement, tooling requirements, and assembly behaviour.

Engineering support for retaining ring selection

A standard retaining ring won't always meet the requirements of an application. Load conditions, geometry, installation method, and material selection can all determine whether a standard part is suitable for the assembly. In those cases, Rotor Clip engineers work with customers to develop custom retaining ring solutions that meet specific application requirements.