Up to roughly 1,000-5,000 units, SLS 3D printing replaces injection molding by saving €10,000-50,000+ in tooling cost and delivering in 3 working days instead of 6-12 weeks. Above that volume, injection molding remains cheaper per part, but 3D printing remains faster, more flexible and has no MOQ.
When is 3D printing cheaper than injection molding?
The math is simple: injection molding has high one-off cost (tooling €10,000-50,000+, qualification, material tests) but low marginal cost per part. 3D printing has no one-off cost but higher marginal cost per part. The break-even sits between 500 and 5,000 parts, depending on complexity and material.
Under 1,000 parts SLS is almost always cheaper. Between 1,000-5,000 it depends on geometry: a simple part tips over to molding earlier, a complex part with undercuts or thin walls stays attractive for SLS longer. Above 5,000-10,000 parts per year injection molding is usually preferable economically.
Important: this math only compares cost per part. The business case is broader. Without a mold you can keep adjusting your design during production — no tool rework, no NRE investment to amortise. For products in time-sensitive markets that’s often decisive.
When is injection molding the right choice?
Injection molding wins at:
- Runs above 10,000 units/year of stable designs
- Materials SLS does not offer (production-grade PC, ABS, PP, glass-clear materials)
- Very thin walls under 1 mm
- Strict food-contact requirements with specific material certificates that don’t exist in SLS powders
- High surface quality as-shipped (high-gloss without polishing)
But even in these cases customers often use SLS for the phase before tooling: bridge production, market validation, the first 100 customers, A/B-testing variants. Only when the design is locked do you order the mold.
Hybrid approach: bridge production
A common strategy: during the first 6-12 months of a product launch you fill demand with SLS prints while in parallel you build the injection mold. Advantages:
- No waiting for tooling — in market from day 1
- Design can still adapt based on customer feedback without modifying the mold
- The €30,000+ tooling outlay shifts to the moment the market is validated
- Production transitions seamlessly once the mold is ready
Our engineers help you frame this hybrid business case — book a conversation to weigh up your run size, lead time and cash flow.