External constant section retaining rings, commonly known as external snap rings, are designed to secure components on a shaft within mechanical assemblies. Installed into a machined shaft groove, the portion of the ring protruding from the groove creates a shoulder that retains components in place. Rotor Clip manufactures constant section snap rings in both external and internal configurations, with this guide focusing specifically on external snap ring designs.

If you work with mechanical assemblies, chances are you’ve come across the terms snap ring and retaining ring. While retaining ring is a broad term covering several designs, Rotor Clip uses snap ring to describe its constant section retaining ring family. This constant section design provides three points of contact with the groove while maintaining a lug-free profile also makes them well suited for applications with limited radial clearance.

In this guide, we’ll take a closer look at how external constant section retaining rings work, their key design features, common applications, and the factors to consider when selecting the right ring for your application.

When selecting a retaining ring for your application, size alone does not determine performance. Ring geometry, installation method, and load distribution within the groove all influence how a ring behaves in your assembly. For example, spiral retaining rings and tapered section rings (circlips) both secure components within a groove, but they achieve retention in fundamentally different ways. Spiral rings rely on a continuous coiled geometry that engages the groove uniformly around the circumference. Circlips use a stamped, lug-based design that compresses into position and locks into place through defined contact points.

In this guide, we’ll walk you through the key differences between each ring design and which one may be the better fit for your requirements.

Do you have an application exposed to corrosion, elevated temperatures, or challenging operating conditions? Stainless steel retaining rings or wave springs may be the solution. Whether you’re specifying retaining rings (circlips & snap rings), spiral rings, or wave springs, stainless steel offers excellent resistance to corrosion while maintaining mechanical stability in service. Compared to uncoated carbon steel, stainless steel is far less prone to corrosion when exposed to moisture and helps preserve its mechanical properties over time.

At Rotor Clip, an extensive inventory of stainless steel grades and specialty alloys is maintained to support a wide range of production requirements. This material availability allows flexibility in meeting a wide range of mechanical, environmental, and performance needs.

Standard retaining rings, or circlips, are designed to secure components and prevent axial movement within a groove. In many applications such as electric motors, automotive drivetrains, and aerospace actuators, assemblies require more than basic retention. Conditions like tolerance stack-up, vibration, and endplay require retaining rings that apply load-bearing force within the groove system rather than simply sit in place. 

Within the tapered section retaining ring family, there are several designs developed to address specific assembly requirements. In this blog, we will focus on two of those designs: beveled and bowed retaining rings. Both are axial tapered section circlips used in applications involving axial play, endplay, and vibration.

If you’re working with a compact assembly that requires preload, positioning, or load control, chances are you’ve used or considered Belleville washers or disc springs. These components are well established in applications where axial force is needed in a limited space. However, their performance is tied to stacked configurations or fixed stamped geometries, which can introduce variability in alignment, assembly, and load consistency.

This variability is a key reason engineers are increasingly selecting wave springs as an alternative. Wave springs use a continuous wave geometry to generate controlled spring force in a single component, removing the need for stacked assemblies and reducing variation associated with multi-part configurations. Compared to Belleville washers and disc springs, this results in more consistent force behavior and simplified assembly. Let’s delve into some of the wave spring options that can replace these types of springs below.

Retaining rings, also referred to as circlips and snap rings, are mechanical fasteners that form fixed shoulders to secure components in place. Retaining rings deform during installation or removal and return to their original shape after installation, allowing them to maintain secure retention within a machined groove.  This makes them a practical fastening solution for applications requiring compact, efficient component retention.

From automotive transmissions to medical devices, retaining rings are used wherever compact shaft or housing retention is needed. Selecting the correct ring type, size, material, and installation method supports long term assembly performance and retention. Evaluating these factors early in the design process helps support proper ring selection and overall assembly function. Rotor Clip engineers can help guide the selection process and identify the right retaining ring solution for your application.

As electric vehicle drivetrains and industrial rotating systems continue to operate at higher rotational speeds, a retaining ring’s ability to maintain stability within an assembly becomes even more critical. At elevated rotational speeds, imbalance can contribute to vibration, noise, and reduced long-term performance. In standard ring designs, uneven mass distribution can amplify these effects, making them less suitable for high-speed applications. 

Rotor Clip high-speed balanced rings are modified tapered-section retaining rings designed for applications where rotational imbalance becomes a limiting factor. In a conventional tapered-section design, the cross-section decreases from the lug toward the gap, creating uneven mass distribution around the circumference. Balanced ring designs address this by optimizing lug geometry to offset material removed by the taper and gap. This results in a more uniform distribution of mass and supporting higher rotational capability compared to standard designs, while maintaining compatibility with standard groove geometries and established assembly methods. 

This modification does not affect installation methods or groove compatibility and uses the same controlled expansion method and installation process as standard circlips. The design instead improves dynamic behavior during rotation, supporting more stable operation at elevated RPM, while delivering a minimum 50% increase in rotational capacity and up to 100% in certain applications. 

These characteristics are especially relevant in electric motor and high-speed rotating assemblies where retaining rings contribute to overall system stability under dynamic load conditions.

Learn how we support e-mobility applications 

Rotor Clip High-Speed Retaining Ring Advantages 

Enhanced Stability 

Rotor Clip high RPM balanced rings provide improved stability and security for high-speed applications, using optimized lug geometry to support more consistent engagement within the groove during operation. This helps maintain ring positioning under dynamic load conditions and reduces the potential for axial movement. 

Reduced Vibration and Noise 

In high RPM rotating systems, imbalance within retaining components can contribute to vibration and noise that affect overall system performance. 

Balanced ring designs support more uniform groove engagement on the shaft, reducing vibration levels and improving operational stability at elevated speeds. This can increase operational speed ranges by a minimum of 30% compared to standard retaining ring configurations. The uniform pressure they apply on the shaft helps minimize vibrations and dampen resonance within an assembly.

Improved Installation Efficiency 

Rotor Clip balanced rings are installed using controlled expansion over a mandrel and standard assembly methods used for tapered section ring designs. 

This supports integration into existing assembly processes without requiring impact tooling or specialized installation equipment. Standard lug holes also allow for straightforward removal and service. 

Other manufacturer ring solutions such as spiral ring with locking features can have limited capability in service removal and assembly flexibility, often requiring specialized tools and difficult installation and removal techniques. Rotor Clip’s tapered design not only saves assembly time but reduces risk of damage to the mating assembly components.  

Cost-Effective Performance 

The geometry improvements that support high-speed operation do not introduce unnecessary manufacturing complexity. 

As a result, balanced ring designs support: 

• Reduced assembly time  

• Lower risk of component damage during installation  

• Fewer service interventions over time  

• Compatibility with existing manufacturing processes  

Why Rotor Clip Balanced Rings? 

Different retaining ring designs vary in how they handle rotational speed, installation methods, and groove compatibility. The comparison below highlights key differences between Rotor Clip high RPM balanced rings and other commonly used retaining ring designs. 

Application Driven Engineering Support 

As the only manufacturer of every ring style, Rotor Clip delivers Application Driven Solutions, working directly with customers to identify the right retaining ring configuration based on operating conditions, groove design, and assembly requirements. For high-speed application requirements, talk to our team.

Engineers who rely on traditional coil and disc springs often face limitations related to axial space, weight, and force consistency. A wave spring is a flat wire compression spring characterized by its wave shape. Unlike traditional coil springs, wave springs generate force through bending rather than torsion. This design allows them to compress and expand efficiently while occupying up to 50% less axial space than traditional compression springs. These springs are used in a wide range of applications, including bearing preload, fluid connectors, mechanical seals, and power transmission systems. 

Wave springs can simplify assembly. Many designs can locate themselves in a bore or on a shaft, reducing the need for extra retaining features. In applications that use stacked disc springs to meet load or travel requirements, a single multi-turn wave spring can often replace the entire stack. This reduces part count, simplifies handling, and lowers the chance of assembly errors. 

Technical Features & Benefits 

Axial Space Savings 

One of the key benefits of wave springs is their ability to save axial space. In static applications, a wave spring typically requires only 50% of the work height needed by a coil spring while delivering an equivalent force. In dynamic applications, space savings are generally around 30% because additional turns are often required to manage bending stresses without fatigue. These differences are a result of multi-turn wave spring design and how the number of turns affects work height. 

Consistent Spring Force 

Spring elements typically exhibit both linear and non-linear force behaviors depending on their deflection. Wave springs provide a broader and flatter linear force region across their deflection range. This allows engineers to achieve more predictable spring forces, which is critical in applications like mechanical seals, where accurate preload balances wear and leakage. Single-turn wave springs typically maintain linear force between 30% and 70% of deflection, while multi-turn designs cover a slightly wider range. Coil and disc springs have narrower linear regions, making it more difficult to maintain consistent force. 

Increased Travel 

When compared to a traditional disc spring, multi-turn wave springs can offer far more travel.   One multi-turn wave spring can replace multiple disc springs used to achieve a specific travel range. While most applications require short travel distances, typically less than 1 mm, wave spring designs can be engineered for much larger travel distances when needed Replacing a stack of disc springs with a single wave spring also reduces the chance of installing the wrong number of components and simplifies assembly. 

Dial-in Spring Rate 

Wave spring stiffness is defined by material thickness, spring material, the number of waves per turn, and the number of turns. Engineers can tune these variables to obtain the required spring rate for a particular application without changing the spring’s overall envelope. Optimizing the number of waves per turn is a practical method to adjust stiffness while maintaining desired load characteristics. 

Dimensional Tolerance Improvements 

Wave springs maintain consistent force over a broader range of deflections, which allows greater flexibility in the dimensional tolerances of spring cavities and mating shafts. When force is predictable across deflection, designers can avoid overly tight tolerances that would otherwise be necessary to meet specific force requirements. This flexibility can reduce manufacturing costs while maintaining performance integrity. 

In the chart above, you can see how a single-turn wave spring, a coil spring, and a multi-turn wave spring behave under load and deflection. Increasing the number of waves per turn changes the spring’s free height and compressed diameter, adding some hysteresis because each wave produces a small amount of friction during compression. These effects can be addressed during design. Free height and diameter can be calculated to meet application requirements, and hysteresis can be minimized by presetting the wave spring, which involves compressing it to its work height over several cycles. 

Highly Customizable  

Unlike stamped parts, which require dedicated tooling, wave springs can be adapted quickly without additional cost or delays. Rotor Clip wave springs are fully customizable and produced to exacting standards to ensure reliable performance. In-house processes allow engineers to adjust material thickness, number of waves, number of turns, alloy selection, end configurations, and other parameters to meet specific application requirements. Vertical integration provides precise control over rolling and coiling, maintaining consistent material properties, and dimensional accuracy.  Specifying high-quality, properly manufactured wave springs ensures predictable force, consistent deflection, and reliable performance while providing the flexibility engineers need for both standard and specialized designs. 

Our engineers will work with you to evaluate your requirements and identify the right spring solution for your application. Contact us to discuss your design.

Wave spring end types play a critical role in how the spring interfaces with mating components, directly impacting load distribution, surface contact, and overall application performance. Wave springs are a type of compression spring designed to provide precise load control while reducing space and weight, using a waveform structure that distributes force through bending rather than torsion. Selecting the correct end type helps minimize surface wear and allows the spring to function as intended within the assembly. 

Key factors engineers should evaluate include: 

• Surface condition of mating components 

•  Required load distribution 

•  Clearance within the assembly 

•  Sensitivity of contact surfaces 

•  Assembly and handling conditions 

Evaluating these factors early in the design process helps align spring configuration with application performance. 

Rotor Clip manufactures single-turn and multi-turn wave springs in sizes ranging from 3 mm to 635 mm, with features that can be customized for specific application requirements. Adjustments to turns, wave count, material thickness, radial dimensions, and especially end type allow engineers to optimize performance, improve load distribution, and accommodate mating components. Because wave springs are coiled rather than stamped, many modifications can be implemented without special tooling, making both standard and custom designs efficient to produce. 

Multi-Turn Wave Spring End Types 

Multi-turn wave springs consist of a continuous series of waves along multiple turns, designed to meet a wide range of force and deflection requirements. These springs can be tailored to specific application needs through adjustments to wave count, number of turns, wire thickness, material selection, and end-type configuration, allowing engineers to achieve the required load, travel, and assembly fit. 

Available end types include: 

Plain Ends 

Plain ends are the standard configuration for multi-turn wave springs. The spring terminates at the next wave peak, providing consistent contact with mating surfaces and uniform load distribution across the spring. 

Shim Ends 

Shim ends include additional flat turns or layers at the top and bottom of the spring. These flat sections help distribute load evenly across the spring’s surface, which is particularly useful when the spring interfaces with: 

• Uneven surfaces, such as grooves, holes, or slots in mating components. 

• Soft materials, including plastics, rubbers, or soft metals, where load needs to be spread over a larger area. 

In certain applications, multiple shim layers can be used to affix the spring into a groove or retain it securely on the mating component, providing additional stability. 

Floating Ends 

Floating ends are cut slightly shorter, so the spring’s end does not rest directly on the adjacent wave peak. This design minimizes concentrated contact points, reducing the potential for scratching or surface damage. Floating ends are particularly beneficial for springs with thicker wire cross-sections or applications where mating surfaces are sensitive. 

Single-Turn Wave Spring End Types 

Single-turn wave springs consist of a single turn with multiple waves, providing reliable compression in a compact axial space. They handle low to high thrust loads and are suited for narrow radial walls, low clearances, and assemblies with ball or roller bearings. They can also replace stacked disc springs, simplifying installation and reducing component count. 

These springs are customizable through wave count, wire thickness, bore or rod diameter, material selection, and end-type configuration. Some designs include a “cling in bore” option to center and maintain alignment. Single-turn wave springs deliver consistent load with tighter tolerances than stamped washers or disc springs, and coiling minimizes material waste. 

Available end types include: 

Overlap Ends 

Overlap ends bring one spring end over the other, eliminating gaps. This configuration prevents tangling during handling, ensures smooth mating with the surface, and avoids concentrated stress points that can occur at open ends. 

Gap-Type Ends 

Gap-type ends create a defined space between the ends of the spring. The size of this gap can be controlled to accommodate assembly clearance requirements or specific mating components that must pass through the spring during operation. 

Patented Flat Ends 

Rotor Clip’s patented flat-end design flattens the ends of the spring, removing sharp corners. This allows the spring to sit evenly against the mating surface, reducing wear and protecting bearings. Flat ends are ideal in preload applications or where minimizing surface stress is critical. 

Rotor Clip delivers Application Driven Solutionsᵀᴹ and has extensive experience designing products for applications across nearly every industry. Our engineers provide on-demand support tailored to your needs. For guidance on selecting the right wave spring and end type, contact an engineer today. 

As demand for retaining rings grew across automotive, aerospace, defense, and general manufacturing industries, Rotor Clip made the strategic decision to welcome Waldes Truarc into the organization in 2009. At the time of the acquisition, Waldes owned Industrial Retaining Ring (IRR), allowing Rotor Clip to assume responsibility for both product lines through a single transition. 

By integrating Waldes’ established designs into Rotor Clip’s manufacturing systems, Rotor Clip expanded its retaining ring portfolio, enhanced material capabilities, and deepened industry expertise, strengthening its ability to support regulated and high-performance markets. 

Technical Gains and Market Coverage 

The integration of Waldes enhanced Rotor Clip’s ability to support retaining solutions across commercial, military, and aerospace standards within a single manufacturing organization. 

Established Part Numbers and Continuity 

With the acquisition of Waldes Truarc and IRR, Rotor Clip gained full ownership of thousands of established part numbers. Engineers can cross-reference these part numbers directly through Rotor Clip’s online search and interchange tools, simplifying ordering and ensuring continuity for assemblies built around legacy designs from Waldes Truarc and IRR. This preserves decades of part history while supporting ongoing supply needs through Rotor Clip’s global production and inventory systems. 

Interchange Example:

Waldes Truarc: N5000-50SPP = Rotor Clip: HO50ST PD

Military and Aerospace Capabilities 

The Waldes Truarc acquisition expanded Rotor Clip’s reach into highly regulated aerospace and defense markets. By incorporating Waldes’ established military specifications, engineering documentation, and designs into its operations, Rotor Clip supports assemblies with ISO 9001 and AS9100 certified components engineered for tight tolerances, traceable processes, and documented quality control. Over the past decade, the company has worked directly with hundreds of aerospace and defense engineers worldwide and continues to support the market with both standard and custom retaining ring solutions. 

Materials and Alloys Expertise 

The acquisition expanded Rotor Clip’s material capabilities, including stainless steels, Inconel, and other specialty alloys. Today, Rotor Clip maintains one of the largest material inventories in the industry, supported by extensive warehouse space of over 100,000 sq. ft. that includes millions of stocked parts across multiple facilities. This enables rapid production of components designed for high-temperature, corrosive, and performance-critical applications across demanding industries. 

Global Infrastructure and Support: 

The acquisition supported Rotor Clip’s continued expansion as a global organization. Today, the company operates manufacturing, warehouse, sales, engineering, and customer service facilities in the Czech Republic, Germany, the United Kingdom, China, and Fort Worth, Texas. These strategically positioned locations provide local technical support, stocked inventory, and streamlined delivery for customers, ensuring that engineers worldwide have access to the parts and expertise they need. 

Today, Rotor Clip is recognized as a leading global manufacturer of retaining rings and is the only company that produces every retaining ring style (circlips, snap rings, spiral rings). Rotor Clip provides engineers with a true one-stop source, supported by in-house manufacturing from wire forming through finished part production. Rotor Clip’s continued growth and investments reflect a long-term commitment to expanding capabilities and supporting customers worldwide. Waldes remains part of Rotor Clip’s history, but Rotor Clip’s scale, focus, and manufacturing strength define who it is today and how it continues to serve the industries that rely on it. 

Learn more and access part number information now.