Circlips are a cost saving alternative to fastening. Such as machined collars on shafts or washer and pin assemblies, still offering the same benefits of a single fastening mechanism by reducing material waste and the number of components.
Circlips provide a simple, reliable and cost-effective method of securing components onto shafts or inside bores. Commonly used as an alternative to machined collars, threaded fasteners, washer-and-pin assemblies and other multi-part fastening systems, circlips can help reduce material use, assembly time and the overall number of components required.
At Bearing King, our collection includes External Circlips and Internal Circlips for a wide range of mechanical, engineering, automotive, manufacturing and maintenance applications. These compact retaining rings are designed to fit into specially machined grooves, creating a secure shoulder that helps prevent components from moving axially during operation.
Whether you are replacing an existing retaining ring or selecting a fastening solution for a new assembly, choosing the correct circlip type and size is essential. Browse the collection to find circlips suitable for securing bearings, gears, pulleys, wheels, bushes and other mechanical parts.
What Are Circlips?
Circlips, sometimes referred to as retaining rings, snap rings or retaining clips, are metal fasteners used to hold components in position. Unlike bolts, nuts or conventional collars, they are installed into a groove on a shaft or within a housing.
Once fitted, the circlip acts as a retaining shoulder. This helps restrict the sideways or axial movement of the component next to it while still allowing the assembly to remain compact.
Circlips are widely used in applications where space is limited or where a component may need to be removed during servicing. Their lightweight construction and straightforward installation make them a practical choice for both original equipment manufacturing and repair work.
Depending on the assembly, the correct solution will normally be either an external circlip or an internal circlip.
What Are External Circlips?
External Circlips are designed to fit around the outside of a shaft. They sit within a groove machined into the shaft and help prevent adjacent components from sliding off or moving beyond a defined position.
During installation, external circlips are expanded using suitable circlip pliers before being positioned over the shaft and released into the groove. Once correctly seated, the ring returns towards its original shape and remains securely located.
External circlips are commonly used to retain:
- Bearings on rotating shafts
- Gears and sprockets
- Pulleys
- Wheels and rollers
- Spacers
- Bushes
- Mechanical linkages
They are suitable for many industrial and mechanical assemblies where a compact external retaining method is required.
What Are Internal Circlips?
Internal Circlips are fitted inside a bore, housing or cylinder. They locate within an internal groove and create a shoulder that helps retain a component inside the opening.
To install an internal circlip, the ring is compressed using circlip pliers and placed into the bore. When released, it expands into the machined groove.
Internal circlips are frequently used to secure:
- Bearings inside housings
- Seals
- Bushes
- Pistons
- Pins
- Mechanical inserts
- Components within cylindrical assemblies
They are particularly useful when the retaining mechanism must sit within the housing rather than around the outside of a shaft.
External Circlips vs Internal Circlips
The main difference between External Circlips and Internal Circlips is where they are installed.
External circlips fit into grooves on the outside of shafts. Internal circlips fit into grooves inside bores or housings.
A simple way to identify the correct type is to look at the component being retained:
- Choose an external circlip when the retaining ring must fit around a shaft.
- Choose an internal circlip when the retaining ring must fit inside a bore or housing.
Although both types perform a similar retaining function, they are shaped and installed differently. An external circlip should not be substituted for an internal model, or vice versa.
Benefits of Using Circlips
Circlips offer several advantages over more complex fastening methods.
Compact design
Because circlips fit directly into machined grooves, they require very little additional space. This makes them useful in compact machinery and tightly arranged mechanical systems.
Reduced component count
A single retaining ring can replace assemblies made from several separate parts. This may simplify both product design and maintenance.
Cost-effective fastening
Circlips can reduce the need for machined collars, threaded shaft ends, nuts, washers or cross-d rilled pin arrangements. This can help lower manufacturing and assembly costs.
Quick installation and removal
When the correct tools are used, circlips can usually be fitted and removed efficiently. This is valuable for machinery that requires routine inspection, repair or bearing replacement.
Reliable component retention
A correctly selected and installed circlip provides a defined retaining shoulder, helping keep bearings and other components in their intended axial position.
Reduced material use
Their simple, lightweight design can help reduce unnecessary material compared with larger retaining components or multi-part fastening systems.
How to Choose the Right Circlip
Selecting the correct circlip involves more than choosing between an internal and external design. The size of the shaft or bore, the groove dimensions and the operating conditions must also be considered.
Before ordering, check:
- Whether the circlip fits a shaft or a bore
- The nominal shaft or bore diameter
- The groove diameter and width
- The thickness of the circlip
- The available installation space
- The expected axial load
- The operating temperature
- The likelihood of corrosion or moisture exposure
- The relevant equipment or manufacturer specification
Where an old circlip is being replaced, use accurate measurements rather than relying only on its visible condition. A worn, distorted or damaged retaining ring may no longer represent its original dimensions.
It is also important to check the groove itself. Even the correct circlip may not perform properly if the groove is worn, damaged, contaminated or incorrectly machined.
Installing Circlips Correctly
Circlip pliers should normally be used to install and remove retaining rings. These tools engage with the holes or lugs at the ends of the circlip and allow the ring to be expanded or compressed in a controlled way.
External circlips are expanded for installation over a shaft, while internal circlips are compressed for fitting inside a bore.
Avoid overstretching or over-compressing the ring. Excessive deformation can weaken the circlip or prevent it from returning to the correct shape.
After installation, check that the circlip is fully seated around the entire groove. A partially fitted ring may become dislodged when the machine is operating.
Eye protection should also be worn during installation and removal, as retaining rings can release suddenly if they slip from the tool.
Common Applications for Circlips
Circlips are used throughout engineering, manufacturing and maintenance. Typical applications include:
- Electric motors
- Gearboxes
- Pumps
- Agricultural machinery
- Automotive systems
- Conveyors
- Power transmission equipment
- Industrial rollers
- Machine tools
- Construction equipment
- Domestic appliances
- Bearing housings
Their versatility makes them suitable for both rotating and stationary assemblies, provided the circlip is correctly matched to the groove and load requirements.
Circlips for Bearings and Mechanical Assemblies
Circlips are often used alongside bearings to control axial movement. An external circlip may secure a bearing or spacer on a shaft, while an internal circlip may retain a bearing within a housing.
However, a circlip should not automatically be treated as a substitute for every type of bearing shoulder or locking arrangement. High-load, high-speed or safety-critical systems may require additional retention methods.
Always follow the machinery manufacturer’s specification and confirm that the selected retaining ring is suitable for the application.
Frequently Asked Questions
What is a circlip used for?
A circlip is used to retain a component on a shaft or inside a housing. It fits into a machined groove and helps prevent bearings, gears, pulleys, bushes or other parts from moving axially.
What is the difference between internal and external circlips?
External circlips fit around shafts, while internal circlips fit inside bores or housings. External versions are expanded during installation, whereas internal versions are compressed.
Can a circlip be reused?
A circlip may sometimes be reused if it remains undamaged and within the manufacturer’s specification. However, rings that are bent, stretched, corroded, cracked or worn should be replaced.
Do I need circlip pliers?
Circlip pliers are strongly recommended. They provide better control during installation and removal and reduce the risk of damaging the circlip, the groove or surrounding components.
How do I measure a circlip?
Measurement depends on whether the ring is internal or external. Check the relevant shaft or bore diameter, along with the groove dimensions and circlip thickness. Where possible, refer to the equipment specification rather than measuring only the removed ring.
Are snap rings and circlips the same?
The terms circlip, snap ring and retaining ring are often used for similar types of fastening components. However, product designs can vary, so the dimensions and intended application should always be checked before ordering.
Shop Circlips at Bearing King
Explore Bearing King’s range of Circlips, including External Circlips for shafts and Internal Circlips for housings and bores. The collection provides practical retaining solutions for bearings, gears, pulleys, bushes and a wide range of mechanical assemblies.
Before purchasing, confirm the circlip type, nominal diameter and groove specification required for your equipment. Choosing the correct size and installing it with suitable tools will help provide secure, dependable component retention.
