Metal Casting API

Metal-casting and foundry maths as an API, computed locally and deterministically — the solidification-time, shrinkage and melt-weight numbers a foundryman, patternmaker or casting designer works a job to. The solidification-time endpoint applies Chvorinov's rule, t = B × (V/A)², where V/A is the casting modulus (volume ÷ cooling surface area) and B is the mould constant (~2–4 min/cm² for sand): a chunky part with little surface for its volume freezes slowly, a thin one fast — and because a riser must stay molten longer than the casting it feeds, its modulus has to be larger, which is the number that sizes it. The pattern-shrinkage endpoint makes the pattern oversize for the metal that shrinks as it cools: pattern = casting dimension × (1 + shrinkage/100), the patternmaker's contraction rule — about 1.0–1.6 % for grey iron, ~2 % for steel and aluminium — so a 100 mm steel feature needs a 102 mm pattern. The melt-weight endpoint gives the casting weight = volume × metal density (iron ~7.2, steel ~7.85, aluminium ~2.70 g/cm³) and the metal to actually pour = casting weight ÷ the casting yield, because the sprue, runners and risers are remelted scrap — a 7 kg iron casting at 70 % yield needs about 10 kg in the ladle. Everything is computed locally and deterministically, so it is instant and private. Ideal for foundry and patternmaking tools, casting-design and estimating apps, and metalworking calculators. Pure local computation — no key, no third-party service, instant. 3 compute endpoints. For a part's weight from its dimensions use a metal-weight API; for welded joints a welding API.