Posted to News on 30th Mar 2026, 11:45
Why circlips and snap rings outperform cotter pins
Are you still relying on cotter pins or traditional fasteners to secure your assemblies? While these methods have been used for generations, modern designs demand solutions that save time, reduce complexity, and secure components against axial and radial forces. Rotor Clip retaining rings (circlips, snap rings, and spiral rings) offer a more advanced approach.
(See Rotor Clip at Machine Building North, 13 May 2026, on stand 79)
They provide compact, cost-effective, and high-performance retention without the extra parts or machining that cotter pins require. Over time, retaining rings has become the preferred choice for engineers seeking stronger, simpler, and more efficient assembly designs.
What are retaining rings and why are they the preferred choice?
Retaining rings, commonly known as circlips or snap rings, are metal fasteners that fit into a groove on a shaft or inside a bore. Once installed, the ring holds components securely in place without the need for additional nuts, washers, or drilled holes.
Compared to cotter pins and traditional fasteners, retaining rings offer several advantages:
Reduced machining and lower cost: Retaining rings only require a groove, which reduces machining steps and assembly time, lowering overall production costs.
Fewer parts: A single retaining ring can replace multiple components, such as a nut, washer, and pin. This simplifies assembly and reduces the risk of installation errors.
Highly customisable: Retaining rings are available in a wide range of sizes, materials, and finishes. Engineers can adjust tolerances, thicknesses, end configurations, and other features to meet the needs of nearly any application.
Compact and efficient assemblies: They eliminate the need for additional hardware, which saves space and weight in the overall design.
Rotor Clip is the only manufacturer of every style of retaining ring, giving engineers an even wider range of options for any application in industries like, but not limited to, aerospace, medical and automotive. Rotor Clip's retaining ring families include: axial tapered section rings (circlips); constant section rings (snap rings); radial retaining rings (e-clips, c-clips and more); and spiral rings.
Cotter pins - function and where they fall short
Cotter pins, also called split pins, are simple metal fasteners with two tines that are inserted through a pre-drilled hole in a shaft, clevis pin or nut. For decades, they have been used to prevent components from sliding out or loosening, particularly in agricultural equipment, general hardware and field-serviceable assemblies.
Cotter pins have several key limitations when compared to retaining rings:
Limited axial load capacity: Cotter pins are designed to resist shear loads but cannot handle significant thrust or axial forces.
Extra-part preparation: Installation requires pre-drilled holes, which adds machining steps and can slightly weaken components.
Space and protrusion issues: The bent ends of cotter pins take up extra space and can catch on tools, clothing, or nearby components.
Not suitable for compact or high-performance assemblies: Cotter pins are best for simple or low-load applications, whereas retaining rings provide secure retention in tight, high-performance, and high-load designs.
Ready to make the change?
If you are considering switching from cotter pins or traditional fasteners to retaining rings, let Rotor Clip engineers guide you. Rotor Clip can collaborate with you to select the ideal ring for your application, including the right size, material, and style.
