Cost & Quoting

Casting and Forging Cost Estimation: Building a Defensible Per-Part Quote

A money-first breakdown of what drives cost per casting or forging, how to build a quote that survives scrutiny, and the estimate errors that erode margin.

Material is the largest line on most casting quotes, and the trap is quoting on net part weight instead of poured weight. If a part finishes at 42 kg but yield is 72 percent, you buy and melt 58 kg. At ductile iron charge cost of 0.55 dollars per kg, the honest material figure is 58 times 0.55 = 31.90 dollars, not 42 times 0.55 = 23.10 dollars, a 38 percent understatement. Then add melt loss: 3 percent oxidizes to dross, so you charge 60 kg to tap 58. Foundry Scrap Cost and the Melt Loss Calculator turn that spread into a real dollar figure per part.

Energy and furnace time are the second driver, and they scale with tonnage melted, not parts shipped. Induction melting of iron consumes roughly 550 to 650 kWh per tonne of liquid metal. At 0.11 dollars per kWh and 600 kWh per tonne, melting costs 66 dollars per tonne, or about 3.83 dollars for the 58 kg poured into one part. Aluminum runs higher per kg because of latent heat, often 700 to 900 kWh per tonne including holding. Use the Furnace Charge Calculator to size the melt so you allocate energy against actual charge weight rather than a flat per-part guess.

Labor and machine time attach at each station: molding, pouring, shakeout, grinding, and heat treat. Price them as a cycle-time rate. If a molding line runs 120 molds per hour at a fully loaded cell rate of 480 dollars per hour, molding cost is 4.00 dollars per mold divided by parts per mold. Grinding and fettling are often underquoted; a part needing 3.5 minutes of hand grinding at a 45 dollars per hour bench rate adds 2.63 dollars. Shakeout throughput matters too, since a bottleneck there idles pouring. The Shakeout Capacity calculator confirms the line rate your labor allocation assumes.

Scrap and rework quietly destroy margin because you pay full material, energy, and labor on a part that ships zero revenue. If your casting scrap rate is 6 percent, every good part must absorb the cost of 0.064 scrapped parts (1 / 0.94 minus 1). On a part costing 45 dollars to produce, that is 2.87 dollars of pure loss baked into each shipped unit. Internal returns get remelted so they cost less than external scrap, but they still cost energy and handling. Foundry Scrap Cost quantifies the remelt-versus-write-off difference so your quote carries the true yield-adjusted burden.

Tooling and die life amortize across the order, and getting the divisor wrong swings the price. A forging die costing 24,000 dollars spread over an estimated 20,000 pieces adds 1.20 dollars per part, but if realistic die life is 12,000 hits, the true amortization is 2.00 dollars. Pattern and core box costs for casting follow the same logic. Always amortize against expected tool life, not order quantity, or a reorder after tooling wears exposes an unquoted refurbishment. The Die Life Estimator gives a defensible hit count so the per-part tooling charge holds up when the customer asks how you got it.

Overhead and yield stack on top as multipliers, and this is where two estimators quoting the same part diverge by 20 percent. Take a direct cost buildup, then apply a plant burden rate, commonly 35 to 60 percent of direct cost for a jobbing foundry, then a margin of 10 to 20 percent. On a 45 dollar direct cost with 45 percent burden and 15 percent margin, the quote is 45 times 1.45 times 1.15 = 75.04 dollars. Document each multiplier separately so a customer challenge on price hits a specific line, not the whole number.

Estimates go wrong most often on three inputs: yield assumed too high, scrap assumed too low, and energy priced at last year's utility rate. A yield estimate off by 8 points, quoting 80 percent when the part really runs 72 percent, understates melt weight by 10 percent and can erase the entire margin. Peg yield from actual Casting Yield data on similar geometry, not optimism. Same for pour weight: the Pour Weight Calculator anchors your material line to real ladle demand rather than the finished-part drawing weight.

Build the quote as a stacked sheet so every dollar traces to an input: poured material, melt loss, energy per tonne, molding and pouring labor, cores and sand, finishing labor, tooling amortization, scrap burden, then overhead and margin. Sand is small but real, near 0.30 to 0.80 dollars per part depending on core content, and the Sand Usage Calculator sizes it. When a customer pushes back, you show the line, not a lump sum. That transparency is what makes a quote defensible and keeps you from cutting price on a part that was correctly costed the first time.

Published 2026-07-01.