Quick Q: How do I compare MIM vs CNC vs investment casting cost?
Calculate total cost of ownership (TCO) over the expected program life: TCO = Tooling cost + (Per-part cost × Total volume) + (Quality cost × Total volume). MIM wins at high volumes (tooling cost spread over many parts). CNC wins at low volumes (no tooling investment). Investment casting falls between, with moderate tooling and moderate per-part cost.
TCO comparison template:
| Cost Element |
MIM |
CNC Machining |
Investment Casting |
| Tooling cost |
$15,000 |
$500 (fixtures, programming) |
$6,500 |
| Per-part cost (10 g, 316L) |
$0.65 |
$4.50 |
$1.20 |
| Annual volume |
50,000 |
50,000 |
50,000 |
| Program life (years) |
3 |
3 |
3 |
| Total production cost (3 yr) |
$15,000 + ($0.65 × 150k) = $112,500 |
$500 + ($4.50 × 150k) = $675,500 |
$6,500 + ($1.20 × 150k) = $186,500 |
Volume breakeven analysis:
| Annual Volume |
MIM |
CNC |
Investment Casting |
| 1,000/yr |
$15.65/part ($15 tool + $0.65) |
$4.85/part |
$6.20/part — CNC wins |
| 10,000/yr |
$2.15/part |
$4.55/part |
$1.85/part — Investment casting wins |
| 50,000/yr |
$0.95/part |
$4.51/part |
$1.33/part — MIM wins |
| 100,000/yr |
$0.80/part |
$4.51/part |
$1.27/part — MIM wins decisively |
Hidden costs to include in TCO:
| Hidden Cost |
MIM |
CNC |
Investment Casting |
| Secondary machining |
Low (near net shape) |
None (already machined) |
Moderate (gate removal, surface finish) |
| Scrap / rework cost per part |
$0.03-0.05 |
$0.01-0.02 |
$0.05-0.12 |
| Inspection cost per part |
$0.03-0.08 |
$0.01-0.03 |
$0.05-0.10 |
| Inventory holding cost |
Low (stable supply) |
Moderate |
Low |
| Design change cost |
High (mold modification) |
Low (reprogram) |
Moderate (wax die modification) |