Safety Rings for Shafts

Snap Rings for Shafts Made from Round Spring Wire

Snap rings for shafts are used to retain components axially on shafts, axles or pins. They are installed in a suitable shaft groove and form a positive mechanical stop. This prevents rollers, bushes, bearings, spacers, gears or levers from moving unintentionally along the shaft.

The open rings are made from round spring wire. For installation, the snap ring is expanded elastically and moved along the shaft to the intended groove. Once it reaches the groove, it springs back and remains securely seated through its own spring tension.

Snap rings provide a compact and removable axial retaining solution without requiring a thread, nut or additional cover.

Meaning of the Specifications in the Product Table

The shaft diameter alone is not sufficient for reliable selection. The wire diameter, groove dimensions, contact surface and axial loads must also be considered.

How to Select the Correct Snap Ring

Proceed in the following order:

1. Determine the shaft diameter: Select a snap ring whose dimension a corresponds to the nominal shaft diameter.

2. Check the groove: The groove diameter and width must suit the ring size and wire diameter d.

3. Check the installation space: The ring must be capable of being expanded sufficiently and moved along the shaft to the groove.

4. Assess the axial load: Consider static loads, alternating loads, impacts and vibration.

5. Check the contact surface: The retained component should contact the ring with a sufficiently wide and flat end face.

6. Select the material: Humidity, temperature, cleaning agents and other surrounding media affect the choice of material.

The load capacity of the complete retaining arrangement does not depend on the snap ring alone. The shaft material, groove geometry, distance between the groove and shaft end, and the contact surface of the retained component also influence the permissible axial load.

Difference from Circlips to DIN 471

Snap rings for shafts and circlips to DIN 471 perform a similar function but have different designs.

Snap rings are made from round spring wire and do not have mounting lugs. Circlips to DIN 471 are manufactured from flat material and normally have two mounting holes for circlip pliers.

The two versions are not directly interchangeable. Groove dimensions, installation method and contact geometry must match the specific ring design. Standardised versions with mounting holes can be found in our circlips for shafts to DIN 471 range.

Groove Design Recommendations

The shaft groove must be clean, accurately machined and free from burrs. A groove that is too narrow may prevent the ring from engaging completely. An excessively wide groove increases axial play.

The distance between the groove and the end of the shaft must be sufficient for the remaining shaft shoulder to withstand the applied axial load. If the edge distance is too small, the shoulder may fail even though the snap ring itself has sufficient strength.

Large chamfers or radii on the retained component may reduce the effective contact area. Where necessary, a sufficiently rigid support washer can distribute the axial load more evenly.

Installation and Removal

Before installation, the snap ring, shaft and groove should be clean and free from damage. The ring should only be expanded as far as necessary to move it over the shaft. Excessive expansion may cause permanent deformation.

After installation, check that the ring is fully seated around its complete circumference. A partially engaged snap ring must not be loaded.

A tool suitable for the ring size should be used for installation and removal. Screwdrivers or other unsuitable tools may damage the ring, groove or surrounding components.

Eye protection is recommended because the tensioned ring may spring away from the tool or shaft if handled incorrectly.

Spring Steel or Stainless Spring Steel

Versions made from spring steel 1.1200 are suitable for many general applications in dry or moderately exposed environments.

Snap rings made from stainless spring steel 1.4310 offer improved corrosion resistance and are generally more suitable for humid areas, outdoor applications or regularly cleaned equipment.

Suitability must be assessed separately where the ring is exposed to salt water, chlorides, acids or aggressive cleaning agents.

Frequently Asked Questions About Snap Rings for Shafts

How is the correct size determined?

The shaft diameter a is the main selection value. The wire diameter, inside diameter, opening dimension and groove geometry must also be checked.

Can the snap ring be installed without a groove?

No. A correctly designed shaft groove is required for reliable axial retention.

Can snap rings be reused?

Only if they have not been permanently expanded, deformed, damaged, worn or affected by corrosion. A new ring should be used for safety-relevant connections.

Are circlip pliers required?

These snap rings do not have mounting lugs. The correct tool therefore depends on the ring size, installation space and design.

Further retaining and connecting components can be found in our spring elements overview.