Circlips

About Circlips

Circlips, also known as retaining rings or snap rings, are precision-engineered fastening components that play a vital role in securing assemblies on shafts or within bored housings. These resilient metal rings feature a spring-loaded design that allows them to compress or expand during installation, then lock securely 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 across countless mechanical applications in automotive repair, industrial maintenance, and workshop environments.

Tooled-Up.com stocks comprehensive circlip assortments from trusted brands including Sealey and Draper, providing tradespeople and DIY enthusiasts with the variety needed for diverse repair and maintenance tasks. The 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 without specialist tools). These assortments typically contain hundreds of pieces spanning common metric sizes from as small as 3mm up to 40mm or larger, ensuring you'll have the right circlip on hand when carrying out repairs, assembly work, or equipment servicing.

Professional-grade circlip assortments come organised in compartmented storage cases for easy identification and selection, with clearly labelled size markings that save valuable time during jobs. Whether you're working on gearboxes, pumps, electric motors, hydraulic equipment, or general machinery, having a comprehensive circlip selection in your workshop or van prevents project delays and eliminates the frustration of missing fasteners. 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 where components are subjected to significant loads and vibration.

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 such as gearboxes and pump housings.

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. Commonly used in automotive transmissions and industrial machinery.

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 and removal but generally provides lower retention force than traditional circlips, making them suitable for less demanding applications.

Circlip Pliers

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

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. Groove dimensions must match circlip specifications for proper function.

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 without permanent deformation.

Who Uses Circlips?

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

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 using digital callipers – internal circlips require the bore diameter, whilst external circlips require the shaft diameter. Selecting the wrong type will result in improper fit and potential component failure.

Assortment Size and Range: Consider purchasing comprehensive assortments containing multiple sizes rather than individual circlips. Available at Tooled-Up, assortments from Sealey and Draper typically range from 200 to 800 pieces, covering metric sizes from 3mm up to 40mm or more. Professional tradespeople working on diverse equipment should consider larger 800-piece assortments to ensure adequate stock of commonly used sizes, whilst home users may find 200-285 piece assortments more economical.

E-Clips for Quick Assembly: 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 or vibration.

Storage Organisation: Look for assortments supplied in compartmented plastic storage cases with clearly labelled size markings. This organisation system prevents frustration, saves time when selecting the correct circlip, and keeps your workshop or van tidy. Well-organised storage is essential for mobile tradespeople working across multiple sites.

Material Quality: Ensure circlips are manufactured from hardened spring steel for durability and consistent retention force. Quality circlips from established brands like Sealey and Draper provide reliable performance and can be safely reused if not damaged, offering better value over time.

Popular Accessories

• Circlip pliers sets – including both internal and external configurations with interchangeable tips for various sizes
• Digital callipers or micrometers – for accurate measurement of shaft and bore diameters to ensure correct circlip selection
• Pin punch sets – for removing stubborn circlips from recessed grooves and tight spaces
• Safety glasses and gloves – essential PPE when working with spring-loaded fasteners to prevent injury
• Small parts trays – to prevent losing circlips and small components during disassembly work
• Bearing pullers – often used alongside circlips when servicing bearing assemblies and removing pressed components
• Degreasing agents and cleaning brushes – for cleaning grooves and ensuring proper circlip seating free from debris
• Storage cases and organisers – additional compartmented cases for workshop organisation and mobile tool storage

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 capable of causing serious eye injuries. The HSE recommends appropriate eye protection when working with any spring-loaded fasteners, and this applies particularly to circlip installation and removal.

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 at high speed. Work in a controlled manner, maintain a firm grip on tools throughout the installation process, and keep your face away from the plane of the circlip. When possible, shield the circlip with your hand or a cloth during installation to contain it if it slips.

Never reuse circlips that show signs of deformation, corrosion, or fatigue. A weakened circlip may fail in service, potentially causing mechanical failure, component separation, or safety hazards. Always inspect retention grooves for damage, wear, or debris that could prevent proper seating, and ensure circlips are fully seated in their grooves before returning equipment to service. For safety-critical applications such as vehicle suspension components or machinery that could cause injury if it fails, always fit new circlips rather than reusing removed ones.

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, reduced spring tension, or any distortion of the circlip holes. For critical applications such as automotive safety components or industrial machinery where failure could cause injury, it's best practice to install new circlips rather than reusing old ones. The small cost of a new circlip is insignificant compared to potential equipment failure.

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 manufactured from the 1970s onwards. The assortments stocked at Tooled-Up from Sealey and Draper contain metric sizes covering the most common applications encountered in professional and DIY work, typically ranging from 3mm to 40mm or larger.

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 specialised pliers have shaped tips that fit into the small holes on circlips, allowing controlled compression or expansion. However, E-clips can be pushed on by hand or with pliers and prised off without specialist tools, though a small screwdriver or pick is helpful for removal. Attempting to fit standard circlips without proper pliers is dangerous and risks injury.

Why won't my circlip stay in the groove?
Common causes include incorrect sizing (circlip too small or too large for the shaft or bore), damaged or incorrect groove dimensions, debris or corrosion in the groove preventing proper seating, or a deformed circlip that has lost its spring tension. Ensure you're using the correct size for your application by measuring with digital callipers, clean the groove thoroughly with degreaser, inspect for damage, and verify the groove depth meets specifications. If the groove is worn or damaged, it may need re-machining.

How do I measure which size circlip I need?
For external circlips, measure the shaft diameter at the location where the circlip will fit. For internal circlips, measure the bore diameter. Use digital callipers for accuracy, measuring to the nearest 0.1mm, 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. If you're between sizes, refer to engineering drawings or manufacturer specifications for the correct groove dimensions.