A hardness tester presses a calibrated indenter into a metal surface under a known load and measures the resulting indentation to rate resistance to permanent deformation. The right scale — Rockwell, Brinell or Vickers/micro — depends on the material, section thickness and surface finish.
Which Hardness Scale to Use
| Scale | Indenter | Best for | Standard |
|---|---|---|---|
| Rockwell | Diamond cone or steel ball | Fast QC on finished parts, heat-treated steel | ASTM E18 / ISO 6508 |
| Brinell | Tungsten carbide ball | Castings, forgings, coarse-grain or non-uniform material | ASTM E10 / ISO 6506 |
| Vickers / Micro | Diamond pyramid | Thin sections, coatings, weld zones, case depth | ASTM E384 / ISO 6507 |
Rockwell Hardness Testing
Rockwell reads hardness directly from indentation depth, making it the fastest scale for production QC. NL Scientific manufactures the Rockwell Hardness Tester (Touch Screen), built to ASTM E18 and ISO 6508.
Brinell Hardness Testing
Brinell’s larger ball indentation averages out local variation, making it suited to castings and coarse-structure material. NL Scientific manufactures the Electronic Digital Brinell Hardness Tester (Touch Screen), built to ASTM E10 and ISO 6506.
Vickers & Micro Hardness Testing
Vickers and micro-hardness use a diamond pyramid indenter for thin sections, coatings and localised zones such as weld heat-affected areas. NL Scientific manufactures the Micro Hardness Tester (Touch Screen) and the Vickers Hardness Tester (Touch Screen), built to ASTM E384 and ISO 6507.
Standards & Accreditation
NL Scientific hardness testers are built to ASTM E18 / ISO 6508 (Rockwell), ASTM E10 / ISO 6506 (Brinell) and ASTM E384 / ISO 6507 (Vickers/micro), with calibration traceable through our ISO/IEC 17025 (SAMM 835) accredited laboratory. Browse the full steel testing range for grips, extensometers and universal testing machines used alongside hardness testing in a factory QC lab.
Frequently Asked Questions
Rockwell or Brinell — which should I choose?
Use Rockwell for fast, direct-reading QC on finished or heat-treated parts. Use Brinell when the material has a coarse or non-uniform structure (castings, forgings) where a larger indentation gives a more representative average.
When is micro-hardness needed instead of Rockwell or Brinell?
Micro-hardness (Vickers at low load) is needed when the test area is too thin or too small for a standard indenter — coatings, case-hardened layers, weld zones and metallurgical cross-sections.
Need the right hardness tester for your laboratory? Contact NL Scientific for a quotation — Asia’s leading manufacturer of civil engineering and material testing equipment, shipping worldwide.

