Providing High Quality, Specialty Product Solutions for Over 100 Years
... Roll Easy with FRANTZ®
Sterling Armor®

In the end, "all things being equal"
...may not be a valid statement.

FRANTZ Manufacturing proudly introduces Sterling Armor® — the alternative to stainless steel.

In a direct response to customer requests, FRANTZ engineers have developed a low carbon steel ball that has the best attributes of stainless steel.

With surface hardness near 70Rc, Sterling Armor® is not a plating. Using FRANTZ' patented* manufacturing process, and control of time, temperature and gaseous composition, a ball surface is created that has higher scuff and wear resistance than 300 stainless.

Tested for over 1200 hours in salt fog, Sterling Armor® just keeps on rolling — which makes Sterling Armor® ideal in caustic environments.

With a wide variety of sizes available, Sterling Armor® has almost endless applications. Corrosion resistance, magnetic, "no pit" or even aesthetic (Sterling Armor® results in a pleasing gloss black finish), Sterling Armor® is the solution.

Best of all, Sterling Armor® offers a price advantage over stainless steel balls — we dare say a significant advantage. Call us for a quote on your application. We think you'll be delighted.

Corrosion Resistance Properties (Typical)

Hydraulic Oils
52100 ChromeEP------------FG
440C Stainless------EPPEEEE
302 StainlessEE--------E------
316 StainlessEEEEPPEEEE
Sterling Armor®EEEE----------E

E = Excellent • G = Good • F = Fair • P = Poor • -- = Will not withstand conditions

Grades and Tolerances - Inches (Typical)


Size Range
in Inches
Deviation from
Spherical Form
in Inches
Lot Diameter 
Variation in
Maximum Surface
Roughness*  in
Micro-inches "Ra"
4001/8" - 1".0004± .00048.0
5001/8" - 1".0005± .00058.0
10001/8" - 1".001± .00110.0
20001/8" - 1".002± .00212.0

Grades and Tolerances - Metric (Typical)


Size Range
Deviation from
Form in
Lot Diameter
Variation in
Maximum Surface
Roughness*  in
Micro-meters "Ra"
4004 - 25.4.0102± .0102.203
5004 - 25.4.0127± .0127.203
10004 - 25.4.025± .025.254
20004 - 25.4.051± .051.305
* Maximum surface roughness visual comparison

The FRANTZ® Sterling Armor® Process is a patented manufacturing process that controls time, temperature and gaseous composition creating a surface with superior scuff and wear resistance. Sterling Armor® provides a complete and uniform barrier, imparting a tough, hard diffusion layer capable of withstanding thousands of hours in salt fog testing.

Load Bearing Sterling Armor®
This process is designed for light-loading applications such as light roller conveyors, polymer bearing applications, and applications involving abrasion or wear characteristics.

Non-load Sterling Armor®
This process is well-suited for inertia type systems, such as inertia shut-off switches, seat belt inertia systems, etc. This may also be used for polymer-bearing applications if loading allows.

Product Selector
Click Here
Impact Testing
Steel Conveyor Wheels
Impact Rating

FRANTZ goes the extra mile to provide the industry’s best conveyor wheels!
Click here to learn more.
My Shopping Cart

Quality Certifications &
Industry Standards
Terms & Conditions of Use     |       2022 FRANTZ Manufacturing Co.
1000 Series - Crimping Tool300 Series - Crimping Tool620 Series - Crimping ToolABEC-1 Core Precision BearingsAbout FRANTZAbout FRANTZ ManufacturingABOUT USAbsentee PolicyAdvertising InformationBall Bearing Sheaves, Idler, Pulley and Guide WheelsBall TransfersBall TransfersBALLSBearing Packaging OptionsBrochures & LiteratureBurnishing MediaBurnishing MediaCareersCAREERSChamfered BearingsCompetitor DefectsCompetitor Match-UpContact Felt Seal Conveyor Bearing ProtectionContact FRANTZ ManufacturingCONTACT USContact Your Sales RepresentativeConversion FactorsConveyor Bearing and Conveyor Wheel QualityConveyor Bearing CatalogConveyor Bearing Mounting SpecificationsConveyor Bearing NomenclatureConveyor BearingsConveyor BearingsConveyor BearingsConveyor Roller Mounting TypesConveyor Wheel CatalogConveyor WheelsConveyor WheelsConveyor WheelsConveyor Wheels / Skate WheelsCore Non-Precision BearingsCustom Conveyor Roller DetailsCustom Conveyor RollersCustom Machined and Cold Formed Steel SpacersCustom Machined SpacersCustomer Service EmailEasy Glider™ Ball Transfers and Ball CastersEconomy Grade Hardened Steel BallsEconomy Grade Hardened Steel BallsEmployee InformationFitment Tooling InformationFlanged and Straight Faced IronGrip AdaptersFlanged Unground Non-Precision BearingsFlexible Spending Plan SummaryFractions to DecimalsFRANTZ Garage Door InformationFRANTZ Health Plan (2009)FRANTZ Health Plan AmendmentFRANTZ Insert ToolsFRANTZ SpecialtiesGEN II® Semi-Precision Conveyor BearingsGenII® Core Semi-Precision BearingsGenStar® 4003 Series Precision Conveyor BearingsGenStar® 5000 Series Precision Conveyor BearingsGenStar® Eliminator BearingsGenStar® Precision BearingsGenStar® Precision Conveyor BearingsHardened Carbon Steel BallsHardened Carbon Steel BallsHoliday ScheduleHOMEIdler GuideIL Equal Opportunity StatementInformación TécnicaInventory OverstockMaps and Directions to FRANTZ ManufacturingMeasurementMetric Conveyor WheelsMetric Flanged Unground Non-Precision BearingsMetric GEN II® Semi-Precision Conveyor BearingsMillimeters to InchesNewsOur QualityOur WarrantyOverhead Conveyor ComponentsPower Swage 2.5” Flanged BearingsPrecision ABEC-1 - Machined BearingsPrecision Drilled BallsPrecision Ground Drilled BallsPress and Swage Fit ToolingPress and Swage Fit ToolingPress Fit Conveyor Bearing MountsPress ReleasesPrivacy NoticePrivacy StatementProduct CatalogsProduct IndexesProduct SelectorsRadial Thrust Conveyor BearingsRegreasable & High Temp Conveyor BearingsRegreasable Conveyor BearingsRegreasable Conveyor BearingsRESOURCESSafety RulesServices BrochureSheave CatalogSheavesSheavesSlip and Swage Fit ToolingSlip and Swage Fit Tooling DetailsSoft Ground Polished BallsSoft Ground Polished Steel BallsSprocketed CDLR Conveyor Roller BearingsStainless Steel Ball TransfersStainless Steel BallsStainless Steel BallsStainless Steel Conveyor BearingsStainless Steel Skate WheelsSteel Ball GlossarySteel Ball PackagingSteel Ball QualitySteel BallsSterling Armor®Sterling Armor®Sterling Armor®Sterling Armor®Straight Faced Semi-Precision BearingsStraight Faced Unground Non-Precision BearingsSwage Fit Conveyor Bearing MountsSwage Fit Conveyor Bearing MountsTapered Conveyor Roller BearingsTechnical InformationTechnical InformationTerms and Conditions of UseTOOLSTube ID and GaugeVideosWHAT'S NEWWhat’s New at FRANTZWide Flanged Unground Non-Precision BearingsWork Rules