Circlips & Retaining Rings

Circlips & Retaining Rings

Circlips (retaining rings) are sprung metal rings that seat in a groove machined into a shaft or bore to retain components in their axial position. They replace more complex retention methods — shoulder plates, threaded collars, and pin assemblies — with a single, simple component that can be installed or removed with circlip pliers. Circlips are used extensively throughout machinery, automotive, and industrial equipment manufacturing and maintenance. AIMS Industrial supplies circlips and retaining rings in metric and imperial sizes for maintenance and engineering applications across Australia.

Types of Circlips

• External circlips (shaft circlips): Seat in a groove on the outside diameter of a shaft. The ring closes inward when installed, bearing against the groove walls to retain a component — bearing, pulley, or collar — on the shaft. Installed and removed using external circlip pliers that engage the tangs of the ring.
• Internal circlips (bore circlips): Seat in a groove on the inside diameter of a bore or housing. The ring expands outward into the groove, retaining a component installed within the bore. Installed and removed with internal circlip pliers. Common for retaining bearings in housings and for retaining snap rings in bores.
• Spiral retaining rings: Coiled spring wire rather than a flat stamped ring. Can be installed without special pliers and provide more uniform groove loading. Used in applications with limited access or where standard circlip tang access is restricted.
• Bowed circlips: A flat circlip with a slight bow that provides axial spring force — takes up end float in the retained component rather than simply stopping it. Used in precision assemblies where controlled axial preload is needed.

Material Options

Standard circlips are manufactured from carbon spring steel — phosphate treated or bright finish. Stainless steel circlips (grade 302 or 316) are used in corrosive environments, food processing, marine applications, and wherever carbon steel would rust and contaminate the surrounding assembly. Stainless circlips are slightly less springy than carbon steel equivalents — confirm the application's retention load against the stainless ring's rated force before substituting.

Metric and Imperial Sizes

Circlips are dimensioned by the shaft diameter (external) or bore diameter (internal) they fit. Metric sizes follow the DIN 471 (external) and DIN 472 (internal) standards; imperial sizes follow equivalent inch standards. Both series are common in Australian industry — older machinery and imported American equipment typically uses imperial; European and modern equipment uses metric.

Installation and Removal

Always use the correct circlip pliers — the right tip style (straight or angled) and the correct tip diameter for the ring tangs. Forcing circlips with incorrect pliers causes the ring to spring off unpredictably or distorts the ring beyond its elastic limit, compromising retention. Never reuse a circlip that has been overstressed or deformed — replace it with a new ring.

Order Circlips from AIMS Industrial

AIMS Industrial stocks external and internal circlips in metric and imperial sizes, in carbon steel and stainless steel. For unusual sizes or large quantities, contact our team.