Rockwell hardness number

{
  "id": "MLC-T-OAG-003183",
  "term": "Rockwell hardness number",
  "field": "Oil and gas",
  "definition": "A measure of a material's resistance to indentation, indicating its hardness. It is determined by pressing a standardized indenter, such as a diamond cone or a hardened steel ball, into the material's surface under a specific load and measuring the depth of the resulting impression. For oilfield equipment in sour service, NACE standard MR0175/ISO 15156 limits the maximum hardness, often to 22 HRC for carbon and low-alloy steels, to prevent sulfide stress cracking.",
  "subject": "Production",
  "url": "https://mlchart.com/terminology/oil-and-gas/rockwell-hardness-number/"
}