Circlips vs. Snap Rings: Understanding the Differences 

4 mins read

When it comes to securing rotating or moving parts within machinery, engineers often encounter the choice between two distinct components – circlips and snap rings.

(Image credit: Rotor Clip)

Despite their apparent similarities, these components exhibit unique characteristics that cater to specific engineering needs. This online post delves into the distinctions between circlips (tapered section rings) and snap rings (constant section rings), highlighting their designs, functions, and the varied applications where each demonstrates its advantages. 

Circlips: Versatile and Efficient

Circlips, whether axially or radially installed, exemplify versatility and efficiency in fastening solutions. Axial circlips offer robust thrust loading capabilities and secure retention with lug holes for easy installation and removal. Their ability to make almost complete circular contact with the groove when installed ensures higher thrust loadings compared to alternative fastening methods. For specialised applications, consider exploring Rotor Clip’s beveled and bowed circlips for further innovation and tailored solutions.

Key Features of Axial Circlips (Tapered Section Rings) 

  • Make almost complete circular contact with the groove, allowing for higher thrust loadings than other fastening methods.
  • Have lug holes for ease of installation and removal with circlip pliers, applicators, or dispensers. Simple tooling allows for automated / high speed assembly.
  • Provide more of a shoulder with which to retain a component or assembly than snap rings.
  • Available in a variety of high-quality materials and finishes to suit any application requirements.
  • Sizes range from:
  • Standard .040” to 15” (1 mm to 1000 mm)
  • Custom .040” to 47” (1 mm to 1200 mm)
  • Available in Inch, Metric, DIN, ANSI, and JIS.

Radial installed circlips combine simplicity, choice of configurations and a functional design. Since radial rings do not extend as far around the circumference of the groove as their axial counterparts, they accommodate less force. Therefore, when thrust loading capabilities are a secondary consideration and an assembly necessitates installation in a radial direction, radial circlips may be the right choice. 

Key Features of Radial Circlips (Tapered Section Rings) 

  • Variety of configurations [e-rings, c-clips, poodle rings] for applications including options for extra retention, space savings/low clearance or to handle high rotational speeds.
  • Easy to install manually or with retaining ring applicators and dispensers.
  • Cost-effective way to provide a secure solution compared to other types of fastening methods.
  • Available in a variety of high-quality materials and finishes to suit any application requirements.
  • Sizes range from:
  • Standard .040” to 2” (1 mm to 1000 mm)
  • Custom rings outside of these ranges are possible. Inquire with our technical sales team for more information.
  • Available in Inch, Metric, DIN, ANSI, and JIS.

Circlips are versatile components that excel at fitting into tight spaces. They come in various configurations, including internal and external types, with options like tapered or bowed designs. Circlips also offer flexibility in size, material, and finish, such as carbon steel, stainless steel, and phosphor bronze with coatings like zinc plating for corrosion resistance. This adaptability allows circlips to meet diverse industry requirements. Whether securing components, absorbing vibrations, or preventing axial movement, the versatility of circlips makes them ideal for an array of applications and industries.

Circlip Applications

In the automotive sector, circlips are commonly used to secure components like gears, bearings, and shafts within transmissions and engines. In electronic devices, circlips securely hold components in place, such as PCBs and connectors, ensuring proper functioning and longevity. In industrial machinery, circlips play a vital role in securing rotating shafts, bearings, and gears, ensuring smooth and efficient operation. Circlips are also essential in aerospace applications, where they effectively secure critical parts like hydraulic cylinders and actuators. With such widespread usage across most industries, circlips have become an integral component in ensuring the performance and reliability of applications. Because of their cost effectiveness and simplicity, tapered section rings are the most common retaining ring style on the market globally.

Snap Rings: Strength and Security 

Snap rings, also known as constant section rings, are manufactured with a uniform width along their circumference, providing three points of contact with the groove. Snap rings excel in applications with tight clearances or limited space, thanks to their lug-free design. Customers frequently choose snap rings due to their robust cross-section, which enhances their ability to withstand impact loads effectively. Designed to provide constant contact that is uniform across a range of deflections, the portion of the ring protruding from the groove (also known as the shoulder) securely holds an assembly in place. 

Features of Snap Rings

  • Uniform width across circumference
  • Excel in applications with tight clearances or limited space because of lug free design
  • Easily installed – do not need special tools but some configurations have notches on the end for easier installation.
  • Simple automation allows for production assembly flexibility
  • Sizes range from:
  • Standard: .157 to 10” (4 mm to 150 mm)
  • Custom: .157” to 15” (4 mm to 380 mm)

Snap Ring Applications 

Snap rings are used in the off-highway, agricultural equipment and automotive industry for various applications including securing piston pins, clutch assemblies, and suspension components. Moreover, snap rings are employed in the manufacturing of industrial machinery, appliances, and power tools to firmly hold components like bearings, shafts, and gears in place; especially when impact loading is at play. They are commonly utilised in heavy-duty applications that require high strength and stability, as their constant section design provides consistent pressure distribution.

Key Differences 

To help you decide which option to choose, consider the following factors: 

Space Limitations: Snap rings excel in applications with tight clearances and limited space due to their lug-free design. The absence of lugs also reduces the risk of interference or obstruction with other components in tight or compact assemblies. Circlips require more clearance for installation because they have lugs or lug holes that protrude from the outer edge, which increase the overall dimensions of the circlips, making it necessary to have additional space to accommodate them during installations.

Load-Bearing Capacity: Circlips excel in applications requiring higher thrust loadings and extra retention, making them suitable for heavy-duty scenarios. Snap rings feature heavy ring shear and heavy-duty sections, providing robust load-bearing capacities and higher rotational capabilities, making them ideal for demanding applications.

Installation and Removal: Circlips offer simplicity in installation and removal, facilitated by lugs and lug holes, where pliers can be used to expand the ring over a shaft or compress it into a housing. Snap rings lack lug holes but do not require special tooling for installation and removal, although some feature notches on the end of the ring to make installation easier. In either use case, simple automation can expand or contract the ring over a tapered shaft or plug to allow for high-speed, production assembly.

Additional Considerations Materials: 

Both circlips and snap rings are commonly crafted from materials like stainless steel and carbon steel. However, for enhanced performance in specific conditions, Rotor Clip offers special grade materials such as Beryllium Copper or Inconel. These materials offer durability and reliability, especially in changing environments with temperature variations or corrosive elements.

Design Flexibility: 

Circlips offer a high degree of design flexibility as they can be easily tailored to accommodate a variety of shaft and bore sizes. Their shape and lugs enable adaptability to different dimensions, providing versatility in various assembly designs. This flexibility allows engineers to use circlips across a variety of applications without the need for significant adjustments to the grooves. The uniform cross-sectional thickness of snap rings may require more precise groove dimensions for optimal installation.