{
  "name": "newlife · sheet-metal unfold",
  "summary": "Flat blank length and weight for a bent sheet-metal part, from material, thickness, bend radius and angle. Free, no key, no account.",
  "units": "millimetre / kilogram / degree",
  "k_factor_source": "newlife default (declared, not a standard)",
  "disclaimer": "Reference calculation. Validate against your own flat pattern before cutting.",
  "generated": "2026-08-13",
  "version": "1.0.0",
  "license": "Data and formulas are free to use. No standard is reproduced here.",
  "human_ui": {
    "es": "https://www.newlifesolutions.dev/herramientas/desarrollo-chapa",
    "en": "https://www.newlifesolutions.dev/en/tools/sheet-metal-unfold",
    "de": "https://www.newlifesolutions.dev/de/werkzeuge/blech-abwicklung"
  },
  "endpoints": {
    "spec": "https://www.newlifesolutions.dev/agent/chapa/unfold-spec.json",
    "case": "https://www.newlifesolutions.dev/agent/chapa/cases/{material}/{thickness_mm}/{angle_deg}.json",
    "mcp_tool": "https://www.newlifesolutions.dev/agent/mcp/chapa_unfold.json"
  },
  "bend_angle_convention": "degrees away from flat (90 = right angle). Not the included angle.",
  "k_factor_default": 0.45,
  "k_factor_note": "The same declared default K is used for every material in this catalogue. Material only changes density (weight) and the advisory minimum radius — not the developed length.",
  "materials": [
    {
      "id": "S235JR",
      "label": "S235JR — acero estructural",
      "density_kg_m3": 7850,
      "min_bend_radius_factor": 1,
      "note": "Density is a physical property. The minimum-radius factor is an advisory rule of thumb."
    },
    {
      "id": "S355J2",
      "label": "S355J2 — acero alta resistencia",
      "density_kg_m3": 7850,
      "min_bend_radius_factor": 1.5,
      "note": "Density is a physical property. The minimum-radius factor is an advisory rule of thumb."
    },
    {
      "id": "AISI304",
      "label": "AISI 304 — inoxidable",
      "density_kg_m3": 7900,
      "min_bend_radius_factor": 1,
      "note": "Density is a physical property. The minimum-radius factor is an advisory rule of thumb."
    },
    {
      "id": "EN-AW-5754",
      "label": "EN AW-5754 — aluminio",
      "density_kg_m3": 2670,
      "min_bend_radius_factor": 0.8,
      "note": "Density is a physical property. The minimum-radius factor is an advisory rule of thumb."
    },
    {
      "id": "Cu-ETP",
      "label": "Cu-ETP — cobre",
      "density_kg_m3": 8930,
      "min_bend_radius_factor": 0.6,
      "note": "Density is a physical property. The minimum-radius factor is an advisory rule of thumb."
    }
  ],
  "thicknesses_mm": [
    0.8,
    1,
    1.5,
    2,
    2.5,
    3,
    4,
    5,
    6,
    8,
    10
  ],
  "precomputed_angles_deg": [
    30,
    45,
    60,
    90,
    120,
    135
  ],
  "note": "Angles and thicknesses outside these lists are not errors — compute them from unfold-spec.json."
}