This technical information has been contributed by
USA Tolerance Rings

New Tolerance Rings Enable Better Performance at Extreme Temperatures, Manufacturer Says

USA Tolerance Rings’ Xtreme Hastelloy® rings helped Baker Hughes Centrilift during the development of an extreme-temperature motor for an oil field pumping system by providing a tight fit between dissimilar parts across a wide temperature range.
Photo courtesy of USA Tolerance Rings.

The rings are reported to handle temperatures to 900 degrees Fahrenheit

PENNINGTON, N.J.—USA Tolerance Rings, reported to be the only producer of tolerance rings in the United States, recently announced the availability of its Xtreme Series Tolerance Rings. Manufactured using Hastelloy® C-276, the new rings will enable designers to improve part performance at extreme temperatures and conditions, according to a release from the manufacturer.

“We have had applications utilizing our Xtreme Series Tolerance Rings to replace elastomers in highly corrosive environments to absorb shock and vibration on silicon carbide thrust bearings,” said Joe Trainer, division manager at USA Tolerance Rings, in the release. “Some customers are using Xtreme Series Tolerance Rings in high temperature applications (575 degrees F), where elastomers tend to break down or outgas.”

Company representatives say that customers have already benefited from deploying Xtreme Series Tolerance Rings in designs that formerly used elastomers for bearing centering and chassis stabilization in extreme working conditions. The tolerance rings, they say, will enable Baker Hughes Centrilift in Claremore, Oklahoma to design equipment that will withstand temperature ranges up to 900 degrees Fahrenheit (482 degrees Centigrade).

“USA Tolerance Rings’ Hastelloy® rings solved the problem,” said John Knapp, senior product engineer for Baker Hughes Centrilift. “During the development of an extreme-temperature motor for an oil field pumping system that was to operate a mile and a half underground, we encountered temperatures that defeated all of our existing bearing designs. USA Tolerance Rings’ Hastelloy® rings solved the problem by providing tight fit between dissimilar parts across a very large temperature range while enduring high pressures, vibration, and temperatures that destroyed all of our other bearing designs. They’re also easy to assemble, which is a benefit to any manufacturing process.”

USA Tolerance Rings (, founded in 1961, offers a wide range of tolerance rings designed to allow for thermal growth, bearing misalignment, and other bearing and mounting issues.

USA Tolerance Rings and Xtreme Series Tolerance Rings are either registered trademarks or trademarks of USA Tolerance Rings in the United States and other countries. Hastelloy is a registered trademark of Haynes International.

The Tolerance Ring: A Circular, Springlike Frictional Fastener for Mounting Round Components

The tolerance ring is a precision-engineered device made from a thin spring steel strip of material into which waves, corrugations or bumps are formed. The strips are cut to length and curled into the ring shape. The waves are either facing inward or outward to accommodate different applications. The AN style, waves facing inward, is designed so that the ends can be closed and fitted into a bore or tube, and is self-retaining when released. The BN style, waves facing outward, is designed so that when the ends are opened, it will slip over a shaft and also be self-retaining when released.

The waveforms are designed to exert a holding force, yet allow for ease of assembly between mating components. This closed wave configuration is typically very strong, with the strongest part being the shoulders or closed ends of the wave. When the tolerance ring is assembled between mating components, each wave is elastically deflected, resulting in holding force. The holding ability of the ring is the resultant force of all the waves and the coefficient of friction with the mating components.

How will a tolerance ring help with thermal growth and contraction?
When materials have different coefficients of thermal expansion (CTE), the annular space between them will expand and contract with temperature changes. A tolerance ring placed between the inner component (i.e., ball bearing) and outer component (i.e., aluminum or plastic housing) will act like a radial spring and compensate for the growth and contraction occurring between the different materials. This provides the holding or “mating” of cylindrical components throughout temperature ranges.

Source: USA Tolerance Rings

This technical information has been contributed by
USA Tolerance Rings

Home |  About Us |  Back To Technical Library |  Contact Us
Copyright © 1996-2010 All Rights Reserved.
General or Technical Questions? E-mail