curl --request POST \
  --url https://api.iotools.cloud/v1/tool/hardness-scale-converter \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "sourceScale": "HV",
  "hardnessValue": "300"
}
'

{
  "tool": "hardness-scale-converter",
  "tool_version": "1.0.1",
  "outputs": {
    "results": [
      {
        "scale": "Mohs",
        "value": "4.4"
      },
      {
        "scale": "Vickers (HV)",
        "value": "300"
      },
      {
        "scale": "Brinell (HB)",
        "value": "284"
      },
      {
        "scale": "Rockwell C (HRC)",
        "value": "29"
      },
      {
        "scale": "Rockwell B (HRB)",
        "value": "105"
      },
      {
        "scale": "Rockwell A (HRA)",
        "value": "65.2"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}