Rockwell Hardness Testing (HRC / HRB)
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
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A direct-reading indentation hardness test measuring the permanent depth of penetration produced by a diamond spheroconical indenter (Scale C) or steel ball (Scale B).
Technical Explanation & Metallurgical Principles
Rockwell hardness testing provides rapid, digital hardness readings without optical microscope measurement. The Rockwell C scale (HRC, 150 kgf load with 120° diamond cone) is universally referenced for hardened and tempered alloy steels and case-hardened gear teeth, as well as for verifying the NACE MR0175 maximum 22 HRC sour service threshold.
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| Rockwell C (HRC) | 120° diamond cone with 150 kgf major load |
| Rockwell B (HRB) | 1/16" steel ball with 100 kgf load (for softer annealed metals) |
| Sour Gas Cap | Max 22 HRC for carbon steel per NACE MR0175 |
Application at Jayesh Forge (Rajkot Plant)
Used in our Rajkot metallurgical lab for rapid verification of quenched, tempered, and induction-hardened components.
Related Materials, Standards & Products
Related Metallurgical & Testing Terms
Brinell Hardness Testing (HBW)
A standardized hardness test that presses a 10mm tungsten carbide ball indenter into the metal surface under a 3000 kgf load to measure indentation diameter.
Quenching and Tempering (Q&T / Hardening)
A two-stage thermal strengthening process: rapid liquid cooling from austenitizing temperature to form martensite, followed by reheating to restore toughness.
NACE MR0175 / ISO 15156 Sour Service Standard
The international standard defining material requirements for metallic equipment used in oil and gas production environments containing corrosive hydrogen sulfide (H2S).
Questions Regarding Rockwell Hardness Testing (HRC / HRB)
22 HRC corresponds to approximately 237 to 241 HBW (Brinell) or 248 HV10 (Vickers).
Request a Forging Quote with Rockwell Hardness Testing (HRC / HRB) Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.