Internal Circlip

  • Internal Retaining Rings
  • DIN 472 / ASME B18.27
  • Spring Steel / Stainless Steel

Category

Internal circlips, also known as internal retaining rings, internal snap rings, or circlips for bores, are spring steel fasteners designed to be installed into a machined groove on the inside diameter of a cylindrical housing or bore. Their primary function is to prevent components such as bearings, gears, or piston pins from moving axially within the housing, ensuring precise positioning and reliable operation under dynamic loads.

Applicable Standards

Standard Description
DIN 472 Internal circlips (retaining rings for bores) – metric series, nominal diameters 8mm to 950mm
GB/T 893 Chinese national standard for internal circlips (equivalent to DIN 472)
ASME B18.27 Inch series retaining rings for North American applications
BS 3673-4:1977 British standard specification for carbon steel retaining rings

Materials & Surface Finishes

Material Properties Surface Finish Options Typical Applications
Spring Steel (65Mn, 60Si2MnA, C67S) High strength, excellent flexibility, fatigue-resistant Phosphate and oil (standard), black oxide, zinc plating General industrial, automotive, machinery
Stainless Steel (304 / A2) Good corrosion resistance, non-magnetic Passivated, plain Food processing, medical equipment, marine
Stainless Steel (316 / A4) Superior corrosion resistance Passivated, plain Chemical processing, coastal applications

Common Applications

Industry Specific Applications
Automotive Transmission assemblies, piston pin retainers, axle shafts
Industrial Machinery Gearboxes, hydraulic cylinders, pneumatic actuators, bearing housings
Electric Motors Bearing retention on rotor shafts
Aerospace High-reliability components requiring precise axial positioning
Hydraulic & Pneumatic Systems Piston rod positioning, cylinder end caps, valve assemblies
Renewable Energy Wind turbine gearboxes and rotating assemblies
Construction Equipment Heavy machinery gearbox and drive train components