G10 is a steel ball precision grade. It is not a material name, a diameter or a certification. Keeping those distinctions clear is an important first step in preparing a useful bearing ball enquiry.
Material and precision describe different things
AISI 52100, GCr15 and 100Cr6 are material designations associated with high-carbon chromium bearing steel in different standards systems. G10 refers to ball precision. A purchase request should state both the required material designation and the required precision grade.
A diameter such as 4.763 mm adds another piece of information: the nominal size. It does not tell the supplier the permitted dimensional variation. The applicable standard, drawing and acceptance requirements remain necessary.
Do not use the grade as a complete inspection plan
A grade label is a starting point for agreement, not a complete account of the inspection your project needs. Ask which standard and edition govern the grade designation, which characteristics will be measured, and what records are required for acceptance.
If the project also specifies hardness, surface condition, batch identification or material documentation, list those requirements separately. An instrument photograph shows equipment; it does not establish the result of a particular production batch.
What BOYA currently confirms
BOYA’s current focus is G10 chrome steel balls. Featured dimensions are 3.969 mm, 4.763 mm and 6.35 mm, with their common inch designations shown on the product page. These are featured sizes, not a statement that only three sizes can be considered.
The full grade and diameter ranges, detailed tolerances, hardness and surface roughness require confirmation. We do not publish numerical limits without supporting product documentation.
A better enquiry
Write material, grade and diameter in separate fields. Add the governing standard and drawing when available. Include quantity, application and any special acceptance criteria, then ask the supplier to identify anything that needs clarification.
Review the chrome steel ball product page or send your specification.