# BOYA Industries

> Precision steel balls and industrial components supplied through manufacturing partners in China. G10 chrome steel bearing balls are the main focus; G5 is available on request.

## Company and supply

- Brand: BOYA Industries.
- Legal entity: 伯牙（泰安）信息科技有限公司.
- BOYA coordinates procurement, partner production, quality requirements and export delivery. BOYA is not the owner of the partner factories.
- Manufacturing partner certifications must not be attributed to BOYA as its own certifications.
- Sales contact: sales@boyaglobe.com; +86 132 3589 3308.
- Office: 2nd Floor, Lujing Xintiandi Commercial Complex, Ningyang County, Tai’an, Shandong, China.

## Manufacturing partner certification

- ISO 9001:2015: Manufacturing of metal balls and their raw materials, steel wires and ball billets; manufacturing of non-metallic balls (ceramic balls). Certificate dates: 2024-07-03 to 2027-07-02.
- IATF 16949:2016: Production of bearing steel balls. Certificate dates: 2025-03-17 to 2028-03-16. Exclusion: Product design.
- These certificates belong to the manufacturing partner, not BOYA. Confirm the applicable manufacturing site and order scope when requesting quality documents.

## Chrome steel bearing balls

- Materials: AISI 52100 / GCr15 / 100Cr6.
- Main grade: G10. G5 is available on request.
- Featured sizes: 5/32 inch (≈3.9688 mm); 3/16 inch (4.7625 mm); 1/4 inch (6.35 mm).
- Diameter range: 0.50–82.55 mm, with other sizes within this range custom ordered. Confirm grade, diameter, material and acceptance requirements together when requesting a quotation.
- A ball precision grade is not a material designation or a single nominal-diameter tolerance.

## Carbon and stainless steel ball families

### Carbon Steel Balls

- material: AISI 1010 / 1015; AISI 1085.
- diameterRange: 0.5–50 mm.
- grade: G100–G1000.
- Processing options: Polished; Heat-treated; Copper plated; Zinc plated; Nickel plated.
- These are family ranges, not confirmation of every material, size, grade and treatment combination. Specify the alloy and operating conditions in the enquiry.

### Stainless Steel Balls

- material: 400 series: AISI 420A / 420B / 420C / 440C; 300 series: AISI 302 / 304 / 304L / 316 / 316L.
- diameterRange: 0.5–150 mm.
- grade: G10–G1000.
- Processing options: Polished; Heat-treated — hardenable grades; Passivated.
- These are family ranges, not confirmation of every material, size, grade and treatment combination. Specify the alloy and operating conditions in the enquiry.

## G5 specification limits

- Ball diameter variation: ≤0.13 μm.
- Deviation from spherical form: ≤0.13 μm.
- Ball lot diameter variation: ≤0.25 μm.
- Surface roughness: Ra ≤0.014 μm.

## Finished-ball inspection example

- One 6.35 mm GCr15 lot, inspected on 2026-10-15.
- Inspection basis: GB/T 308.1-2013 · GB/T 34891-2017 · JB/T 7363-2023.
- Ball gauge (lot size deviation) — requirement: Per process requirements; recorded result: ±0 (+0.2) μm.
- Surface quality — requirement: JB/T 10861-2008 · G10; recorded result: Pass.
- Ball diameter variation — requirement: ≤0.25 μm; recorded result: 0.05 μm.
- Ball lot diameter variation — requirement: ≤0.5 μm; recorded result: 0.05 μm.
- Deviation from spherical form — requirement: ≤0.25 μm; recorded result: 0.057 μm, 0.062 μm, 0.075 μm, 0.076 μm, 0.082 μm.
- Surface roughness — requirement: ≤0.02 μm; recorded result: 0.015 μm.
- Single-ball vibration — requirement: ≤31 dB; recorded result: 26.7 dB, 25.0 dB, 26.2 dB, 26.7 dB, 27.2 dB.
- Tempered martensitic core structure (rating) — requirement: 1–4; recorded result: 3, 3, 3, 3, 3.
- Hardness — requirement: 61–66 HRC; recorded result: 64.4 HRC, 64.7 HRC, 64.6 HRC, 64.8 HRC, 64.9 HRC.
- Crushing load — requirement: ≥21.27 kN; recorded result: 42.42 kN.
- Lot measurements are separate from the G5 specification limits above and do not establish limits for every G10 diameter.

## Products and purchasing

- [Chrome steel bearing balls](https://www.boyaglobe.com/products/chrome-steel-balls/): Materials, featured sizes, grade limits, inspection example and RFQ links.
- [Precision steel balls](https://www.boyaglobe.com/products/precision-balls/): Material-based overview of chrome, carbon and stainless steel balls.
- [Carbon steel balls](https://www.boyaglobe.com/products/carbon-steel-balls/): Material and processing options; supply combinations are agreed in the quotation.
- [Stainless steel balls](https://www.boyaglobe.com/products/stainless-steel-balls/): 300-series and hardenable 400-series options; select the alloy for the operating conditions.
- [Size and weight chart](https://www.boyaglobe.com/resources/steel-ball-size-weight-chart/): Inch and metric labels, approximate weights and quantity conversions.
- [Quality and inspection](https://www.boyaglobe.com/quality/): Inspection methods and the finished-ball inspection example.
- [Partner certifications](https://www.boyaglobe.com/quality/certifications/): Certificate scopes and dates; partner-held certifications.
- [Distributor enquiries](https://www.boyaglobe.com/distributors/): Supply coordination for steel ball distributors.
- [Frequently asked questions](https://www.boyaglobe.com/faq/): Technical selection and ordering questions.
- [How to specify steel balls in an RFQ](https://www.boyaglobe.com/resources/articles/how-to-specify-steel-balls-in-an-rfq/): A practical checklist for material, grade, diameter, quantity and the details that make a steel ball quotation useful.
- [Metric vs inch steel ball sizes](https://www.boyaglobe.com/resources/articles/metric-vs-inch-steel-ball-sizes/): Understand the difference between an exact inch conversion and a rounded metric size label before specifying a precision ball.
- [What does G10 mean for steel balls?](https://www.boyaglobe.com/resources/articles/what-does-g10-mean-for-steel-balls/): Keep precision grade, steel designation and nominal diameter separate when preparing a bearing ball specification.
- [About BOYA](https://www.boyaglobe.com/about/): Company identity and supply coordination role.
- [Request a quote](https://www.boyaglobe.com/rfq/): Provide material, diameter, grade, quantity, application, destination and any drawings.

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