Our metric rings include internal and external circlips (DIN 471 / 472), E-clips, and snap rings that locate and retain components on shafts and in bores without threads. Springing into a machined groove, retaining rings create a reusable, low-profile shoulder for bearings, gears, and pins across machinery and automotive assemblies.

Retaining Rings & Circlips - Metric Sizes

What Is a Retaining Ring?

A retaining ring  also called a circlip or snap ring  is a spring-steel fastener that sits in a machined groove on a shaft or inside a bore to create a shoulder that locates or retains a component axially. Because the ring springs open or closed during installation and then snaps back into the groove, it forms a secure, reusable retention feature without threads, welding, or additional hardware. Retaining rings are essential in compact rotating assemblies where a bolted shoulder would be impractical.

At Metric Specialties we stock external circlips (DIN 471) that fit into a groove on a shaft, internal circlips (DIN 472) that seat inside a bore, E-clips that push on radially from the side, and various snap and wire rings. Circlips are fitted and removed with dedicated circlip pliers that engage the lug holes, springing the ring to clear the groove. The result is a fast, low-cost, low-profile method of retaining bearings, gears, pulleys, pins, and shafts throughout machinery and automotive drivelines.

Key Features and Benefits

• Threadless Retention: Rings snap into a groove to retain components without bolts, welding, or extra hardware.
• Low-Profile Shoulder: The ring creates a compact axial shoulder ideal for tight rotating assemblies.
• Reusable and Serviceable: Circlips can be removed and refitted with pliers, simplifying maintenance.
• Fast Assembly: Springing the ring into its groove is quick and requires no torque control.
• Internal and External Types: Shaft (DIN 471) and bore (DIN 472) rings cover both retention geometries.

Materials and Finishes

• Spring Steel (Phosphate or Zinc): Standard tempered material that provides the springback needed to grip the groove.
• Stainless Steel: Corrosion-resistant rings for outdoor, marine, and hygienic assemblies.

Standards Compliance

• DIN 471  External retaining rings (circlips) for shafts.
• DIN 472  Internal retaining rings (circlips) for bores.
• DIN 6799  E-clips (external retaining rings).

Common Applications and Industries

Retaining rings are found throughout rotating machinery, gearboxes, pumps, and automotive drivelines, where they hold bearings, gears, pulleys, and shafts in position without threads or welding. External circlips (DIN 471) retain components on shafts, while internal circlips (DIN 472) hold bearings and bushes inside bores. E-clips secure light-duty shafts, pins, and rollers in appliances, tools, and mechanisms.

Because they create a compact, reusable shoulder, retaining rings are ideal in space-constrained assemblies and in products that must be serviced repeatedly, from electric motors and power tools to agricultural and industrial equipment. Their low cost and fast installation make them a mainstay of high-volume manufacturing wherever axial retention is needed.

How to Choose the Right Retaining Ring

First determine the geometry: an external circlip for a groove on a shaft, an internal circlip for a groove in a bore, or an E-clip for quick side-fitting onto a light-duty shaft. Then match the ring to the exact groove diameter, shaft or bore size, and thickness specified for the assembly, since correct groove dimensions are essential for secure retention.

Consider the thrust load the ring must resist and choose a ring rated for it, stepping up to a heavier section or a bolted shoulder for high loads. Finally select the material  spring steel for general use or stainless for corrosion resistance  and ensure you have the correct internal or external circlip pliers to fit and remove it.

Size Range and Availability

Available for shaft and bore diameters from 3mm through 300mm across internal, external, and E-clip styles, in spring steel and stainless.

Why Buy From Metric Specialties

As dedicated metric fastener specialists, we retain rings & circlips in the sizes, grades, and finishes that engineers actually need, backed by clear DIN and ISO standard references so you can specify with confidence. Every item is sourced to recognised standards and quality-controlled, giving you consistent thread fit, strength, and corrosion performance across repeat orders.

Whether you need a single item for a repair or bulk quantities for production, our range, technical guidance, and fast dispatch help you find the exact fastener for the job. If you are unsure which size, grade, or finish suits your application, our team can help you match the right product to your load, environment, and standard, so your assemblies are reliable and built to last.

Frequently Asked Questions (FAQs)

1. What is a retaining ring or circlip used for?

Retaining rings locate and hold components axially on a shaft or in a bore without threads  retaining bearings, gears, pulleys, and pins in machinery and automotive drivelines using a machined groove.

2. What is the difference between internal and external circlips?

External circlips (DIN 471) fit into a groove on the outside of a shaft, while internal circlips (DIN 472) seat inside a groove in a bore. Each requires the matching type of circlip pliers.

3. What is an E-clip?

An E-clip (DIN 6799) is an E-shaped external retaining ring that pushes onto a shaft groove from the side rather than over the end. It is quick to fit and common on light-duty shafts and pins.

4. What tool do I need to fit circlips?

Circlips are fitted with circlip pliers that engage the lug holes to spring the ring open (external) or closed (internal). Straight and bent-nose pliers suit different access angles.

5. Are retaining rings reusable?

Circlips can be reused if they remain undeformed and retain their spring tension. Rings that have been over-expanded or bent should be replaced to ensure secure retention.

6. How do I choose the right circlip size?

Select the ring to match the groove diameter and the shaft or bore size specified for the assembly. The ring's free diameter and thickness must correspond to the machined groove dimensions.

7. Are circlips available in stainless steel?

Yes. We stock stainless retaining rings for corrosion-resistant applications in marine, outdoor, food, and medical equipment.

8. What is the difference between a snap ring and a circlip?

The terms are often used interchangeably. Circlip typically refers to the DIN 471/472 lug-hole rings fitted with pliers, while snap rings can include tapered-section and constant-section rings that snap into a groove.

9. Can retaining rings handle axial load?

Yes, within their rated thrust capacity, which depends on ring size, material, and groove design. For heavy thrust loads, choose a ring rated for the load or a bolted shoulder instead.

10. What sizes do you stock for retaining rings?

We stock rings for shaft and bore diameters from 3mm through 300mm across internal, external, and E-clip styles, in spring steel and stainless.