Safety Items

Spring Elements for Retaining, Fastening and Connecting

Spring elements use elastic deformation to hold components, secure pins or create detachable connections. Depending on the design, they are installed in a groove, inserted through a cross hole, pushed onto a component or used as a spring-loaded clamp.

Unlike permanently riveted, welded or bonded connections, many spring elements can be installed quickly and removed again for maintenance. They are therefore particularly suitable for machines, equipment and assemblies that must be dismantled, adjusted or cleaned regularly.

The Febrotec range includes:

• safety springs and Fokker pins,

• linch pins and safety pins,

• snap rings for bores,

• snap rings for shafts,

• spring clips and spring clamps,

• R-clips similar to DIN 11024,

• key rings and split rings.

The correct product group depends on whether a pin, a component on a shaft, a component inside a bore or an object held by spring clamping force must be secured.

Safety Springs and Fokker Pins

Safety springs are inserted through a cross hole in a pin or shaft. Their curved shape grips the component with spring tension and prevents an attached part from sliding off axially.

Typical applications include stub axles, joint pins, wheels, rollers, trailer components and agricultural equipment. The safety spring can normally be installed and removed without additional tools.

Important selection criteria include:

• overall length,

• usable retaining length,

• inside diameter of the spring,

• wire diameter,

• material and surface finish.

The pin or shaft requires a correctly positioned cross hole. The wire diameter and spring geometry must suit both the hole diameter and the outside diameter of the component being secured.

Linch Pins and Safety Pins

Linch pins consist of a straight pin and a movable or spring-loaded retaining loop. The pin is inserted through a cross hole. The loop is then folded over and tensioned around the end of the pin.

This creates a positive and quickly detachable connection. Linch pins are particularly suitable for joints that need to be opened and closed frequently.

Typical applications include:

• trailers and commercial vehicles,

• agricultural and construction machinery,

• linkages and joints,

• height-adjustable equipment,

• machine and equipment construction.

The diameter and usable length of the retaining pin, as well as the available space for the folding loop, are decisive. The cross hole should not be significantly larger than the pin, as this would create unnecessary play.

Snap Rings for Bores

Snap rings for bores are open rings made from round spring wire. They are compressed, inserted into a bore and then allowed to expand into an internal groove.

The section projecting inwards from the groove forms an axial stop. Bearings, bushes, sleeves and other cylindrical components can therefore be retained inside a housing.

Snap rings for bores are not the same as circlips to DIN 472. They do not have mounting lugs and are made from round wire. Depending on the size and installation conditions, a suitable installation tool may be required.

The bore diameter, wire diameter, outside ring diameter, opening dimension and groove geometry must all be considered when selecting the correct ring.

Snap Rings for Shafts

Snap rings for shafts are installed externally on a shaft and engage in a shaft groove through their own spring tension. The ring then forms an axial stop for components mounted on the shaft.

Typical applications include:

• rollers and wheels,

• small bearing arrangements,

• bushes and spacers,

• levers and joints,

• equipment and fixture construction.

These versions are also made from round spring wire and differ from circlips to DIN 471, which are manufactured from flat material and include mounting holes.

Selection is based on the shaft diameter, wire diameter, inside ring diameter and opening dimension. The groove must match the ring geometry and have sufficient distance from the end of the shaft.

Spring Clips and Spring Clamps

Spring clips hold objects through elastic clamping force. They can be used to retain tools, cables, pipes, rods and other cylindrical components.

When the component is inserted, the clip opens elastically. It then springs back and holds the component between its arms. The connection remains detachable and can usually be opened repeatedly.

Spring clips are commonly used in:

• tool holders,

• vehicles and machinery,

• control cabinets,

• household and garden equipment,

• workshop and storage systems.

The outside diameter of the component being held is the main selection criterion. Clamping force, mounting method, material, surface finish and available installation space must also be considered.

Plastic-coated versions can protect sensitive surfaces and reduce noise. Uncoated or zinc-plated spring steel clips are suitable for robust industrial applications.

R-Clips Similar to DIN 11024

R-clips are inserted through a cross hole in a pin or shaft. A straight leg provides positive retention, while the curved spring leg grips the component and holds the clip in position.

They are suitable for quickly detachable connections on machines, trailers, agricultural equipment, linkages and stub axles. No tool is normally required for installation.

The correct size depends on the wire diameter, pin or shaft diameter and usable length. The cross hole must suit the straight leg and be positioned far enough from the end of the shaft.

R-clips should not be forced over pins that are considerably too large. Excessive opening can cause permanent deformation and reduce the retaining effect.

Key Rings and Split Rings

Key rings are made from spring wire wound into overlapping coils. Keys, labels, tags, pendants and small connecting elements can be inserted between the coils.

The overlapping turns prevent attached objects from falling out unintentionally. In addition to their traditional use as key rings, they are suitable for identification tags, sample parts, safety cords and organisational tasks in workshops and production areas.

The ring diameter, wire diameter, material and required load capacity should be considered when selecting the correct version. Key rings are intended for holding and organising small objects and should not be used as load-bearing safety components without technical assessment.

How to Select the Correct Spring Element

The basic selection guide is as follows:

In addition to the design, the dimensions, operating load, installation space, corrosion exposure and required removability must be considered.

Installation and Safety Recommendations

Spring elements must only be deformed within their intended operating range. Excessive bending, compression or twisting can cause permanent deformation.

Before use, check that:

• the element is fully engaged or closed,

• no cracks, corrosion or deformation are present,

• holes and grooves are clean and free from burrs,

• the retained component is supported correctly,

• the spring element does not interfere with moving parts.

For safety-relevant connections, the complete design must be assessed. The retaining effect depends not only on the spring element but also on the pin, shaft, groove, cross hole and applied load.

Frequently Asked Questions About Spring Elements

Are safety springs and R-clips the same?

Both are inserted through a cross hole, but they have different geometries. Selection depends on the pin diameter, installation space and required retaining method.

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

Snap rings are made from round spring wire and normally do not have mounting lugs. Circlips to DIN 471 or DIN 472 are manufactured from flat material and installed using circlip pliers.

Can spring elements be reused?

Many versions are suitable for repeated installation. However, deformed, worn, heavily corroded or damaged components should be replaced.

Which material is suitable for humid environments?

Stainless spring steel is generally more suitable for humid environments than uncoated carbon steel. The actual suitability must nevertheless be assessed according to the specific operating conditions.