Circlips

About Circlips

Circlips, also known as retaining rings or snap rings, are essential fastening components used to secure assemblies on shafts or within bored housings. These precision-engineered metal rings feature a resilient spring design that allows them to compress or expand for installation, then securely lock into machined grooves to prevent axial movement of components. Available in internal and external configurations, circlips provide a reliable, reusable alternative to threaded fasteners, pins, or set screws in countless mechanical applications across automotive, manufacturing, and maintenance sectors.

At TooledUp.com, we stock comprehensive circlip assortments from trusted brands including Sealey and Draper, providing tradespeople and DIY enthusiasts with the variety needed for diverse applications. Our range includes internal circlips (designed to fit inside bored holes), external circlips (which fit onto shafts), and E-clips (C-shaped retainers that push onto grooved shafts). These assortments typically contain hundreds of pieces spanning common metric sizes, ensuring you'll have the right circlip on hand when carrying out repairs, maintenance, or assembly work.

Professional-grade circlip assortments come organised in compartmented storage cases for easy identification and selection. Whether you're working on gearboxes, pumps, electric motors, or hydraulic equipment, having a comprehensive circlip selection in your workshop or van saves valuable time and prevents project delays. High-quality circlips manufactured from hardened spring steel provide the durability and retention force required for both light-duty DIY projects and demanding professional applications.

Jargon Buster

Internal Circlip

A retaining ring designed to fit inside a bored hole or housing, expanding outwards to lock into an internal groove. Used to retain bearings, gears, or other components within assemblies.

External Circlip

A retaining ring that fits onto the outside of a shaft or spindle, compressing inwards to sit within an external groove and prevent axial movement of components.

E-Clip (C-Clip)

A C-shaped or E-shaped retainer that pushes directly onto a grooved shaft without requiring circlip pliers. Offers quick installation but generally lower retention force than traditional circlips.

Circlip Pliers

Specialised hand tools with tips designed to fit into the holes of circlips, allowing controlled compression (for external types) or expansion (for internal types) during installation and removal.

Retention Groove

A precisely machined channel in a shaft or bore designed to accommodate a circlip, providing the seating surface that prevents the clip from moving axially under load.

Spring Steel

A specialised heat-treated steel alloy with high yield strength and elasticity, allowing circlips to maintain their retention force whilst being repeatedly installed and removed.

Who Uses Circlips?

• Automotive mechanics and technicians – for transmission repairs, suspension work, and engine rebuilds
• Plant maintenance engineers – servicing industrial machinery, conveyor systems, and production equipment
• Agricultural engineers – repairing tractors, harvesters, and farm machinery
• Marine mechanics – maintaining boat engines, winches, and marine equipment
• Bicycle and motorcycle mechanics – wheel assemblies, gearboxes, and brake systems
• HVAC engineers – servicing fans, compressors, and air conditioning units
• General maintenance technicians – across manufacturing, facilities management, and site work
• Tool and die makers – assembling jigs, fixtures, and precision tooling
• DIY enthusiasts – home repairs, garden machinery maintenance, and restoration projects

How to Choose the Right Circlips

Internal vs External: Determine whether you need an internal circlip (for bores and housings) or an external circlip (for shafts). Measure the diameter carefully – internal circlips require the bore diameter, whilst external circlips require the shaft diameter.

Size Range: Consider purchasing comprehensive assortments containing multiple sizes rather than individual circlips. Assortments from Sealey and Draper typically range from small metric sizes (as low as 3mm) up to larger diameters (40mm or more), covering the majority of common applications encountered in professional and DIY work.

E-Clips for Convenience: For applications requiring frequent assembly and disassembly, E-clip assortments offer faster installation without specialist pliers. However, they provide lower retention force and are best suited to lower-stress applications where components aren't subjected to significant axial loads.

Assortment Quantity: Professional tradespeople working on diverse equipment should consider larger assortments (300-800 pieces) to ensure adequate stock of commonly used sizes. Home users or those working on specific projects may find smaller 200-piece assortments more economical.

Storage Organisation: Look for assortments supplied in compartmented cases with clearly labelled size markings. This organisation system prevents frustration and saves time when selecting the correct circlip for your application.

Popular Accessories

• Circlip pliers sets – including both internal and external configurations with interchangeable tips
• Pin punch sets – for removing stubborn circlips from recessed grooves
• Digital callipers or micrometers – for accurate measurement of shaft and bore diameters
• Safety glasses and gloves – essential PPE when working with spring-loaded fasteners
• Small parts trays – to prevent losing circlips during disassembly work
• Bearing pullers – often used alongside circlips when servicing bearing assemblies
• Degreasing agents – for cleaning grooves and ensuring proper circlip seating

Safety Information

Circlips are spring-loaded components that store considerable elastic energy when compressed or expanded. Always wear safety glasses or goggles when installing or removing circlips, as they can unexpectedly release and become projectiles causing eye injuries. The HSE recommends appropriate eye protection when working with any spring-loaded fasteners.

Use properly maintained circlip pliers with tips that fit securely into the circlip holes. Worn or damaged pliers can slip during installation, causing the circlip to fly off unpredictably. Work in a controlled manner and maintain a firm grip on tools throughout the installation process.

Never reuse circlips that show signs of deformation, corrosion, or fatigue. A weakened circlip may fail in service, potentially causing mechanical failure or component separation. Always inspect retention grooves for damage or debris that could prevent proper seating, and ensure circlips are fully seated in their grooves before returning equipment to service.

Frequently Asked Questions

Can I reuse circlips after removal?

Generally yes, provided the circlip shows no signs of deformation, damage, or excessive wear. Inspect carefully for bent sections, corrosion, or reduced spring tension. For critical applications or safety-related assemblies, it's best practice to install new circlips rather than reusing old ones.

What's the difference between metric and imperial circlips?

Metric circlips are sized in millimetres and fit metric-dimensioned grooves, whilst imperial circlips use inch measurements. In the UK, metric sizing is standard for most modern equipment. The assortments we stock from Sealey and Draper contain metric sizes covering the most common applications.

Do I need special pliers to fit circlips?

For traditional internal and external circlips, yes – circlip pliers are essential for safe installation and removal. These pliers have specially shaped tips that fit into the holes on circlips. However, E-clips can be pushed on and prised off without specialist tools, though a small screwdriver or pick is helpful for removal.

Why won't my circlip stay in the groove?

Common causes include incorrect sizing (circlip too small or too large), damaged or incorrect groove dimensions, debris in the groove, or a deformed circlip. Ensure you're using the correct size for your application, clean the groove thoroughly, and verify the groove depth meets specifications.

How do I measure which size circlip I need?

For external circlips, measure the shaft diameter where the circlip will fit. For internal circlips, measure the bore diameter. Use digital callipers for accuracy, and select a circlip that matches this measurement. The circlip should fit snugly in the groove with minimal radial play whilst still maintaining spring tension.