JB/T 53331-1999

This standard is used by powder metallurgy bearing manufacturers and quality inspection agencies to grade the quality of 6-6-3 copper-based oil-impregnated bearings. Companies rely on it for internal quality control and product improvement, while customers can select appropriate bearing grades based on it. By defining three quality levels—qualified, first-class, and premium—it provides a basis for quality enhancement and pricing differentiation.

该标准主要用于粉末冶金轴承生产企业和质量检测机构，对6-6-3铜基含油轴承进行质量等级评定。企业依据此标准进行内部质量控制和产品升级，用户可参考该标准选择合适等级的轴承产品。该标准通过划分合格品、一等品和优等品三个等级，为产品质量提升和优质优价提供了依据。

This standard JB/T 53331-1999 specifies the quality grading requirements for powder metallurgy 6-6-3 copper-based oil-impregnated bearings (including cylindrical, flanged cylindrical, and spherical types). It classifies products into three grades: qualified, first-class, and premium, with specific indicators for key items (e.g., oil-impregnated density, oil content, inner diameter), major items (e.g., outer diameter, coaxiality, radial crushing strength, surface hardness), and general items (e.g., appearance, luster, scratches). Test methods reference multiple national standards, including those for density, oil content, and crushing strength. The standard is applicable for quality assessment, enterprise upgrading, and excellence creation, and can serve as a basis for high-quality pricing.

本标准JB/T 53331-1999规定了粉末冶金6-6-3铜基含油轴承（包括筒形、带挡边筒形和球形）的产品质量分等要求。标准将产品分为合格品、一等品和优等品三个等级，并针对关键项目（如含油密度、含油率、内径）、主要项目（如外径、同轴度、径向压溃强度、表面硬度）和一般项目（如外观、光泽、划痕）分别设定了具体指标。检测方法引用多项国家标准，包括含油密度、含油率、压溃强度等测定方法。该标准适用于质量考核、企业升级和创优中的等级评定，也可作为优质优价的依据。