| Standard | Title | Application |
| ISO 6506-1 | Metallic materials — Brinell hardness test — Part 1: Test method | For Brinell hardness (HB), typically used on structural steel and forgings |
| ISO 6507-1 | Metallic materials — Vickers hardness test — Part 1: Test method | For Vickers hardness (HV), suitable for all steel types including thin sections and coatings |
| ISO 6508-1 | Metallic materials — Rockwell hardness test — Part 1: Test method | For Rockwell hardness (HRC, HRB, etc.), widely used for fast and practical testing |
| ISO 4545-1 | Metallic materials — Knoop hardness test — Part 1: Test method | Microhardness test for small, thin specimens or coatings |
| Standard | Title | Notes |
| ASTM E10 | Standard Test Method for Brinell Hardness of Metallic Materials | Equivalent to ISO 6506 |
| ASTM E92 | Standard Test Methods for Vickers Hardness and Knoop Hardness of Metallic Materials | Equivalent to ISO 6507 and 4545 |
| ASTM E18 | Standard Test Methods for Rockwell Hardness of Metallic Materials | Equivalent to ISO 6508; most common method in the US |
| ASTM A370 | Standard Test Methods and Definitions for Mechanical Testing of Steel Products | Contains references for hardness testing as part of broader mechanical testing suite |
| Method | Symbol | Description | Typical Steel Use |
| Brinell | HB | Uses a 10 mm steel/tungsten ball with high load (e.g. 3000 kgf) | Structural steels, forgings, castings |
| Vickers | HV | Diamond pyramid indenter, suitable for all materials | Thin steel sheets, coatings, precise lab tests |
| Rockwell | HRC / HRB | Cone or steel ball under fixed minor and major loads | General-purpose steel testing, fast quality checks |
| Knoop | HK | Elongated diamond pyramid, microhardness | Very small components, thin films or coatings |