Choosing a manufacturing process by quantity

• 1–50 parts: 3D printing (FDM, SLA, SLS/MJF) or CNC. No tooling, so no up-front cost.
• 10–500 parts, production-like: urethane casting from a printed master, or sheet metal for folded parts.
• 500–50,000: injection moulding takes over: a mould costs thousands but the part costs cents.
• Tens of thousands, metal: die casting; extrusion for constant cross-sections; turning for round parts.

The exact crossovers depend on size, wall thickness and material, which is why the table shows every process at each quantity and names the break-even points for your part rather than quoting a rule of thumb.

Temperature, UV, size and wall thickness are checked before a process is allowed to win. A UV-exposed part at 60 °C rules out most resins; a 9 mm wall is a problem for moulding (sink and cycle time); a 600 mm part will not fit most powder-bed printers. Greyed rows say why.

Moulds and dies are paid once, before any part exists. Freeze the design first, prototype in urethane or print, and quote at two or three quantities so you can see where the tooling pays back. Ask suppliers who owns the tooling and what happens if you move production.

The table comes from a parametric model with typical rates — indicative, not quotes. Log the quotes you receive on the run: each is compared with the estimate, which is how the model is checked against reality.