A snap ring or retainer ring is a fastener that holds a bearing in an application in place. A portion of the retaining ring protrudes from the groove to create a shoulder to prevent components from migrating from their position during operation.
As a bearings manufacturing company, we are committed to being a world-class provider for modified and manufactured ball and roller bearing products. At BMC, we stock a wide range of snap ring sizes covering most industry standards to ensure we can meet your delivery request and provide specialty rings such as spiral type, made from stainless steel.
In this article, we discuss snap rings, their purpose, types, and usage.
Snap Rings (Retaining Rings): Purpose, Types, Usage, Advantages
Snap rings are commonly referred to as retaining rings, circlips (circle and clip), or c-clips. They can have a stamped, tapered design. The rings are a type of fastener consisting of a metal ring with open ends which can be "snapped" into place.
Snap rings are a great way to rapidly mount your bearings and have them adequately located axially in your application.
They are often used in external applications to secure parts on grooved shafts, pins, or studs. External circlips are designed to ensure a tight fit into a grove around the outside of a shaft or rod.
Most bearings with a snap ring installed are called out by the nomenclature “NR,” which calls out the manufacturers’ standard, which we match.
Basic Types of Retaining Rings
There are four main types of retaining rings available, each of which may be categorized into:
1. Tapered section - assures contact with the groove along the ring, maybe installed axially (horizontally along with the center point of an axis). Axially assembled retaining rings are installed into machined grooves in housings/bores (internal) or on shafts (external).
2. Constant (snap rings) - feature a uniform, constant section
3. Spiral - axially installed into housings/bores (internal) or onto shafts (external), making 360° contact with the groove.
4. Circular push-on - resembles a toothed washer, commonly fabricated in metal.
Retaining rings exist in many forms, including stamped, spiral, hoop, and radial E-clips, and more.
Listen to Design World as they review the basics of retaining rings and how they work in assemblies...
Source: Design World, (2018, January 10). What are retaining rings? YouTube.
Applications and Advantages of the Snap Ring
Snap rings are found in a variety of applications, including automotive transmissions and hub assemblies.
They offer significant advantages...
- Replace the need for mechanical fasteners (such as nuts, pins, and rivets)
- Reduce the weight of an assembly
- Reduce vibration
- Resilient to wear
- Withstand axial loading (designed for axial installation into the machine grooves)
- Offer a longer service life
- Easily pushed on or off a grooved shaft (without special tools)
- It eliminates the need for threading
- Internal for installation in housings/bores or External for assembly on shafts
BMC can add grooves to bearings and install snap/retainer rings for specific applications.
Retaining Ring Installation
An external ring is installed outside of the shaft and makes contact with its inside diameter.
There are two dimensions to verify before any installation can occur.
1. The inside diameter of the part
2. The overall thickness of the part
Retaining rings will provide the design benefits you need versus other fasteners. Matching a groove is less expensive than using a nuts and bolts approach. Snap rings provide a protrusion or shoulder to retain parts which helps reduce the cost of having to machine a shoulder.
If the accuracy of a shaft or housing does not meet the proper specifications, the performance of your bearings will be affected.
If you have a custom groove needed, we can modify your bearings to whatever print or sample you have. Whether internal or external, finding the suitable rings you need is a "snap" with BMC.