"Luder line" meaning in English

{
  "forms": [
    {
      "form": "Luder lines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Luder line (plural Luder lines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Metallurgy",
          "orig": "en:Metallurgy",
          "parents": [
            "Metals",
            "Technology",
            "Matter",
            "All topics",
            "Chemistry",
            "Nature",
            "Fundamental",
            "Sciences"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A linear surface defect of metal alloys parallel to applied shear stress, as occurs from stretching during milling."
      ],
      "id": "en-Luder_line-en-noun-ULTADKLx",
      "links": [
        [
          "metallurgy",
          "metallurgy"
        ]
      ],
      "raw_glosses": [
        "(metallurgy) A linear surface defect of metal alloys parallel to applied shear stress, as occurs from stretching during milling."
      ],
      "topics": [
        "engineering",
        "metallurgy",
        "natural-sciences",
        "physical-sciences"
      ]
    }
  ],
  "word": "Luder line"
}

{
  "forms": [
    {
      "form": "Luder lines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Luder line (plural Luder lines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Metallurgy"
      ],
      "glosses": [
        "A linear surface defect of metal alloys parallel to applied shear stress, as occurs from stretching during milling."
      ],
      "links": [
        [
          "metallurgy",
          "metallurgy"
        ]
      ],
      "raw_glosses": [
        "(metallurgy) A linear surface defect of metal alloys parallel to applied shear stress, as occurs from stretching during milling."
      ],
      "topics": [
        "engineering",
        "metallurgy",
        "natural-sciences",
        "physical-sciences"
      ]
    }
  ],
  "word": "Luder line"
}