Retaining Ring (Circlip) (ISO / DIN) are specified where the joint requires axial retention of components on shafts and in bores. The sections below cover the typical end-uses by industry, the size and material decisions for each, assembly practice, and the applications this fastener type is not suited to. Stocked across roughly M8 to M100, they cover general to heavy-duty work.
Typical Applications for Retaining Ring (Circlip) — ISO / DIN (Series 151)
The most common settings where these are specified:
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
- Fabrication & metalwork: bench and on-site assembly of steel frames, enclosures and weldments.
- Shafts & gearboxes: retaining bearings, gears and pulleys against axial movement.
- Hydraulic & pneumatic: holding pistons and seals in bores.
How to Specify Retaining Ring (Circlip) — ISO / DIN (Series 151) for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M8–M100; check the full table below for the exact dimensions of each size.
- Groove fit: Specify to the shaft or bore groove diameter; the ring must seat fully in the groove to carry the thrust load.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to ISO / DIN. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Use the correct circlip pliers for the ring size; over-spreading a ring permanently reduces its retention.
- Check the ring is fully seated in the groove around its whole circumference before loading the assembly.
Common Selection Mistakes with Retaining Ring (Circlip) — ISO / DIN (Series 151)
- Machining the groove to the shaft tolerance instead of the groove dimensions in the ring standard.
- Loading a standard ring axially beyond the groove rating instead of moving to a heavy-duty section ring.
Where Retaining Ring (Circlip) — ISO / DIN (Series 151) Are Not the Right Choice
Not for heavy axial thrust beyond the groove rating, and not where the groove cannot be machined to spec.