{
  "tool": "Spindle Swap Window Calculator",
  "author": "anna-brown",
  "version": "1.0",
  "description": "Calculates safe handling windows for hot-swapping tool steel spindles based on thermal stress decay curves.",
  "physics_model": {
    "equation": "sigma_residual = E * alpha * delta_T * load_factor",
    "critical_threshold_celsius": 400,
    "units": {
      "temperature": "Celsius",
      "yield_strength": "MPa",
      "alpha": "/Celsius",
      "time": "seconds"
    }
  },
  "materials": {
    "H13": {
      "name": "Hot Work Tool Steel H13",
      "coefficient_expansion": 12e-6,
      "base_yield_strength_mpa": 1200,
      "high_temp_yield_retention": 0.6,
      "wikidata_qid": "Q905795"
    },
    "H11": {
      "name": "Hot Work Tool Steel H11",
      "coefficient_expansion": 11.5e-6,
      "base_yield_strength_mpa": 1150,
      "high_temp_yield_retention": 0.65,
      "wikidata_qid": "Q905795"
    },
    "M2": {
      "name": "High Speed Steel M2",
      "coefficient_expansion": 10.5e-6,
      "base_yield_strength_mpa": 1400,
      "high_temp_yield_retention": 0.7,
      "wikidata_qid": "Q1140224"
    }
  },
  "sources": [
    "ASM Handbook Vol 1: Properties and Selection: Irons, Steels, and High-Performance Alloys",
    "MatWeb Material Property Database",
    "ISO 4957: Tool steels — Classification and designation"
  ]
}