Overview
ISO 4384-2:2022 specifies parameters for hardness testing of solid materials used in plain bearings, focusing on cast and wrought copper and aluminium alloys, their wrought products and ingots, and tin‑based ingots. It is a supplement to existing hardness-testing standards and defines the extensions and restrictions needed for bearing metals. Because many bearing alloys are heterogeneous, the standard prescribes the Brinell test as the preferred method.
Key Topics
- Scope and applicability
- Solid plain‑bearing materials: cast/wrought Cu and Al alloys, tin‑based ingots, related wrought products and ingots.
- Test method
- Uses the Brinell hardness test (references ISO 6506-1) with specified combinations of indenter diameter, load and dwell time (HBW designations).
- Example notation explained: HBW 5/250/10 = 5 mm ball, 2 452 N test force, 10 s dwell (example provided in the standard).
- Specified test conditions
- Table of preferred HBW conditions for different forms and thicknesses (e.g., bars, tubes, cast alloys with porosity, and ingots).
- Flexibility: alternative indenter/load/duration combinations may be mutually agreed between supplier and customer if standard conditions produce indents that are too large or too small.
- Specimen preparation
- Test area must be metallic bright and conditioned without heating the material.
- Cast and wrought Cu/Al alloys: testing on turned or filed and subsequently prepared surfaces (except hot‑pressed parts).
- Grinding recommendations linked to surface roughness:
- Lead and tin alloys: total profile height R ≤ 6 µm - abrasive paper grain size P240 allowed.
- Copper and aluminium alloys: R ≤ 4 µm - abrasive paper grain size P320 recommended, using suitable lubricant.
- Orientation and anisotropy
- For strongly anisotropic materials, specimen orientation and position within the bearing shall be agreed between customer and supplier.
Applications
- Quality control and incoming inspection for plain bearing manufacturers and suppliers.
- Metallurgical testing in production of Cu/Al bearing alloys and tin‑based ingots.
- Procurement and supplier agreements where agreed test methods, orientation and acceptance criteria are required.
- Third‑party and materials testing laboratories performing Brinell hardness verification on bearing metals.
Related Standards
- ISO 6506-1 - Metallic materials - Brinell hardness test - Test method (normative reference).
- ISO 4287 - Surface texture: profile method (referenced for roughness parameters).
- ISO 4384 series - other parts for plain bearing testing and materials.
For complete test tables, procedural details and normative requirements, consult the full ISO 4384-2:2022 publication.
