Rolling elements · Silicon nitride density and stiffness, centrifugal load, contact stress, fatigue and material data
A ceramic bearing ball is a precision sphere of a technical ceramic such as silicon nitride, zirconia or alumina, used as the rolling element in hybrid or all-ceramic bearings. Ask three things first: the material and its grade of roundness and finish, the bearing and speed it will run in, and the material test data supplied with the batch.
Ceramic balls for rolling bearings: silicon nitride, zirconia and alumina balls in standard and custom sizes. Complete hybrid or ceramic bearings, ceramic valve and grinding balls, and plastic bearings are outside this page.
CNFX editorial research · Sources checked October 11, 2026 · 2 sources
NASA Technical Note D-7794 tested hot-pressed silicon nitride balls of 12.7 mm diameter in a five-ball rolling-contact tester and concluded that silicon nitride running against steel may give fatigue lives comparable to or greater than bearing steel on steel, with spalls similar in appearance to those on steel. The tested material had a bulk density of 3.11 to 3.24 g/cm³ and a modulus of elasticity about 1.5 times that of steel. [1]
Its analysis of 120 mm bore angular-contact bearings showed that replacing steel balls with silicon nitride balls of the same geometry cut centrifugal force by at least 50% but raised Hertz stress at the inner race because of the higher modulus, so bearing life did not improve at 2 to 4 million DN. Lower-mass balls are attractive for very high speeds, and ceramics keep strength and corrosion resistance over a wider temperature range than bearing steels. [1]
Editorial calculation: a 12.7 mm silicon nitride ball has a volume of about 1.07 cm³, so at 3.11–3.24 g/cm³ it weighs about 3.3–3.5 g. [1] Ask the bearing maker whether internal geometry is adjusted for ceramic balls rather than simply substituting them.
Give the supplier the material, ball diameter and tolerance, grade (sphericity and surface finish), quantity, bearing type and speed, operating temperature and media, inspection required (density, hardness, porosity, surface defects) and certificates.
02
Read a supplier material data sheet
Mascera's silicon nitride ball page lists 95% purity, density of at least 3.2 g/cm³, hardness 1,500 HV, Young's modulus 300 GPa, fracture toughness 6.2 MPa·m½, flexural strength over 720 MPa, compressive strength 2,200 MPa, thermal expansion 3.0–3.2 × 10⁻⁶/°C, maximum working temperature 1,200 °C and electrical resistivity over 10¹⁴ Ω·cm, with standard sizes from 1/16 inch (1.588 mm) to 1½ inch (38.1 mm). [2]
The data sheet labels hardness as HV with a unit of MPa, so confirm the hardness scale and test load. Its 1,200 °C figure is a material working temperature, not a bearing rating; ask the bearing maker for the bearing's limit. [2] The NASA work notes that earlier ceramic tests with alumina, silicon carbide and glass ceramic showed fatigue lives much lower than steel, so ask for evidence for the exact material and grade offered. [1]
03
Compare what suppliers offer
Suppliers linked to this page list ceramic bearing balls; each card links to the page reviewed.
Mascera lists black silicon nitride bearing balls in standard inch and metric sizes with a material data sheet; Wintrustek lists silicon nitride bearing balls alongside zirconia and alumina technical ceramics.
04
Trace what defines the ball
This is a functional reference built from the sources cited; it is not one maker's specification.
NASA's test balls were finished to AFBMA grade 10. [1]
Grade, finish and inspection.
05
Fill the specification fields with values for your bearing
A ceramic ball quotation needs values for your bearing. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
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Compiled and source-reviewed by the CNFX editorial team.
Published product pages show what a company offers, not tested performance. Confirm the legal seller, factory and scope for your order. How we source and review
· Page last updated 11 October 2026
Buyer questions
Do silicon nitride balls last longer than steel balls?
NASA tests found fatigue lives comparable to or greater than bearing steel, but a bearing of unchanged geometry did not gain life because the higher modulus raises contact stress. [1]
Why are ceramic balls used at high speed?
Their low density cuts centrifugal force; NASA's analysis found at least a 50% reduction for silicon nitride. [1]
Is the 1,200 °C rating the bearing temperature limit?
No. It is the ceramic material's working temperature on the data sheet, not a bearing rating; ask the bearing maker for the bearing's limit. [2]
Sources and what still needs a direct check
Sources checked 2026-10-11. NASA's Lewis Research Center published the fatigue tests and analysis. Mascera is a supplier listed on this page; its data sheet is used as an example, not a recommendation.
