Can you 3D print working threads?

Yes, but with limitations. FDM printers can produce usable threads from M6 and larger with a 0.4mm nozzle. Use coarse thread pitches, add 0.1-0.3mm tolerance, and print vertically for strongest results. Fine threads below M5 are unreliable on FDM.

Should I print or tap threads?

For holes, printing undersized and tapping with a thread tap gives the best results. For bolts, printed threads work well at M8+ but should be printed vertically. Heat-set inserts are the strongest option for threaded holes.

How much tolerance should I add?

Add 0.15-0.3mm depending on your printer accuracy. Test with a calibration print first. External threads need the major diameter reduced, internal threads need it increased. The gap should allow threads to engage without binding.

What orientation should I print threads in?

Print threaded features vertically (thread axis aligned with Z). This gives the strongest thread engagement since layer lines run around the circumference. Horizontal threads have weak layer adhesion across the thread flanks.

3DPrintCalcs

Thread Calculator — Metric Thread Dimensions for 3D Printing

Calculate metric thread dimensions for 3D printed bolts and threaded holes.

Thread Size

Thread Type

Printer Tolerance

Typical: 0.15-0.3mm

How We Calculate This

ISO Metric Thread Formulas

Thread height H = Pitch x sqrt(3) / 2
Thread depth = 5H / 8
Minor diameter = Major diameter - 2 x Thread depth
Design dimension = Nominal +/- Printer tolerance

External threads are reduced by the tolerance to ensure they fit into standard nuts. Internal threads are enlarged to accommodate standard bolts. The pitch determines the thread spacing and depth.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.