Brinell (HB): Heavy Section Castings and Forgings
Brinell's 10mm steel ball under 3000kg load excels measuring large, rough forgings like 4340 crankshafts and S355 castings where Rockwell indents prove too shallow. HB 200-300 range covers normalized alloy steels; values above HB 450 indicate through-hardened tool steels. Best for parts exceeding 10mm thickness with uneven surfaces.
Rockwell (HRC/HRB): Finished Components and Thin Sections
Rockwell C (HRC 20-70) dominates quality control for heat-treated tools, gears, and fasteners—120° diamond penetrator delivers rapid results on polished surfaces. HRB suits softer annealed grades (HRB 60-100). Superficial scales (30N/15N) test thin sheet metal and surface coatings without substrate influence.
Vickers (HV): Microhardness and Thin Layers
Vickers diamond pyramid (HV 0.3-120kg loads) provides consistent readings across entire hardness spectrum, ideal for weld zones, case depths, and thin coatings where Brinell balls deform unevenly. HV 5-30 microhardness traverses nitrided layers and PVD coatings without edge effects.
Practical Selection Guide
- Foundry/Forging receipts: Brinell (HB) for bulk material acceptance
- Toolroom QC: Rockwell C (HRC) for production release
- Failure analysis: Vickers (HV) for metallurgical examination
- Cross-reference specs: Use Steel Hardness Converter | Nifty Alloys for HB 220 = HRC 22 = HV 235 equivalence
Sharjah Fabrication Reality
UAE workshops verify incoming 4140 at HB 197-237 per EN 10204 3.1 certificates, Rockwell test finished tools at HRC 56-60, and Vickers analyze heat-affected zones post-welding. Multi-scale capability ensures compliance across international project specifications.