Overview
ISO 7852:1983 specifies the shapes and dimensions of plough bolt heads (excluding thread dimensions) used in earth-moving machinery. It covers head form, nominal sizes and tolerances for plough bolts used to mount cutting edges, end bits, bucket teeth and similar wear parts on dozers, graders, scrapers and buckets. The standard supports interchangeability among equipment and components and gives dimensions in millimetres. An annex covers variants with a 90° countersunk angle.
Key topics and requirements
- Scope: Applies to plough bolt head shapes and their dimensional requirements only - thread dimensions are explicitly excluded.
- Head forms: Defines standard head profiles and the corresponding dimensional parameters (for example B, R, D, F, H, h) shown in figures and tabulated in the standard.
- Nominal sizes and tolerances: Provides nominal dimensions and tolerances for each head type to ensure consistent fit and interchangeability across manufacturers.
- Types covered: Main body of the standard lists several standard types (illustrated in figure 1 and table 1). The annex defines additional types for 90° countersunk bolt heads (figure 2 and table 2).
- Units and presentation: Dimensions are presented in millimetres; illustrations and tables form an integral part of the specification.
- Referenced standards: Linked to ISO 6165 (vocabulary/basic types for earth-moving machinery) and cross-references ISO 7129 for cutting-edge shapes.
Practical applications
Who uses ISO 7852 and why:
- OEMs and component manufacturers: to design and produce plough bolts with heads that fit standardized cutting edges, bucket teeth and end bits.
- Maintenance and repair teams: to specify correct replacement bolts ensuring compatibility and safe assembly.
- Purchasing and procurement: to write clear specifications that guarantee interchangeability and reduce part-number proliferation.
- Inspection and quality control: to verify head dimensions and tolerances against an international reference.
- Equipment designers and engineers: to incorporate standardized bolt head dimensions into wear-part and attachment interfaces.
Typical use-cases include mounting cutting edges on graders and dozers, securing bucket teeth on excavators and loaders, and specifying spare parts that must be interchangeable across machine makes.
Related standards
- ISO 6165 - Earth-moving machinery: Basic types and vocabulary (referenced for equipment definitions)
- ISO 7129 - Cutting edges: Principal shapes (related for mating part geometries)
Keywords: ISO 7852, plough bolt heads, earth-moving machinery, plough bolts, bolt head dimensions, interchangeability, bolt head shapes, 90° countersunk plough bolt.