Thin Race Bearing Construction

thin race bearing construction

A KMS Standard thin section plastic ball bearing is constructed with POM acetal races & cage and fitted with SS316 balls. Alternative Materials are available when the standard is deemed unsuitable for the application.

To view sizes of Thin Section Plastic Ball Bearings, click below.

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Thin Race Bearing Materials

Standard Raceway and Retainer:

Acetal POM

(PolyOxy-Methylene) is a superior general purpose engineering polymer that provides an excellent balance of desirable properties that bridge the gap between metals and ordinary plastics.

Alternative Raceway and Retainer Materials:

Kynar® PVDF

(Polyvinylidene Fluoride) is a high performance engineering polymer for use when the Standard Acetal Polymer does not meet the performance requirements of the application. Kynar® provides superior chemical resistance properties that go beyond the standard POM plastic. It is widely selected for critical contact applications for food, pharmaceutical and semiconductor industries for over 20 years.  Kynar® is widely used for membranes, piping, tubes, valves, pumps, vessels, and now BEARINGS.


PEEK (Polyetheretherketone), is a high heat, high performance engineering polymer for use when the Standard Celcon® Acetal Polymer does not meet the performance requirements of the application. PEEK offers chemical and water resistance similar to PPS (Polyphenylene Sulfide), but can operate at higher temperatures. PEEK can be used continuously to 480°F (250°C) and in hot water or steam without permanent loss in physical properties.  

Valox® PBT

Valox® Polyester offers the mechanical performance of Acetal with superior chemical resistance. Valox® polyester resin is a semi-crystalline material based on polybutylene terephthalate (PBT). Valox® resin combines heat and chemical resistance, as well as outstanding electrical properties with exceptional process-ability and surface appearance. 

For complete information on plastic bearing materials click here

Standard Ball Type: 316 Stainless

Alternative Ball Materials: Acetal, Ceramic, Torlon®, Polypropylene.

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Bearing Construction

KMS produces ball bearing race grooves featuring True Race Technology™. We have developed special automated speed lathes for the specific task of machining ball grooves. This procedure removes any molding imperfections and produces a deep ball groove radius that is consistent and concentric for optimum bearing performance and life.

Standard Ball Groove Construction: Radial ball groove

Alternative Ball Groove Construction-  4 Point Contact (gothic arch): KMS offers the unique "XR" series bearing style with 4-point contact deep ball groove geometry. This ball groove design enables the bearing to handle simultaneous radial, axial and moment loading while maintaining stiffness. As a bonus, it also has minimal radial and axial play. The "XR" groove design will not lock up in the presence of off center loads

Double row: KMS offers a double row bearing style that features two rows of balls for increased radial and axial loading capability, increased shaft rigidity and durability.

Two Plastic Bearings

FULL COMPLEMENT & CAGE TYPE CONSTRUCTION: A KMS Thin Section Plastic Ball Bearing is constructed with either a full complement style or with a polymer cage depending on the application requirement and/or availability.

RUN DRY OR LUBRICATED: KMS plastic race bearings are designed to run dry without lubrication. When necessary due to the specifics of the application, a KMS bearing can be supplied with lubrication.

LUBRICATION: When an application requires further reduction in noise or reduction in friction between balls a lubricant can be added. For more technical information regarding approved lubricants, please contact KMS Bearings, Inc.

Shields & Seals

SHIELDS & SEALS: The standard design is open construction. Polymer shields and seals can be provided on a special made to order basis.  A minimum order will apply.

Contact KMS today to find out if a Thin Section Plastic Ball Bearing is the perfect alternative for you!


Plastic Vs Steel

Lightweight: Plastic is five times lighter than steel, thereby reducing the weight and energy to move them.

Read all the benefits of Plastic vs Steel Bearings