Hole size calculator
Printer type
Fit
Goes in by hand, doesn't wobble (lids, plugs).
- gap per side
- 0.15 mm
- Make the hole
- 8.3 mm
Fit
| Fit | FDM | Resin | |
|---|---|---|---|
| Press fit | 0.05 mm | 0.02 mm | Parts pushed in with force, stay put (magnets, bearings, pins). |
| Snug fit | 0.15 mm | 0.05 mm | Goes in by hand, doesn't wobble (lids, plugs). |
| Sliding fit | 0.25 mm | 0.1 mm | Moves freely without play (drawers, sliders, axles). |
| Loose fit | 0.4 mm | 0.2 mm | Easy to put in and take out; print-in-place hinges and gaps. |
Common holes
- M3 screw passes through
- 3.3–3.5 mm
- M3 screw cuts its own thread
- 2.6–2.8 mm
- M3 heat-set insert
- 4.0–4.2 mm (check the insert maker)
- M4 screw passes through
- 4.3–4.5 mm
- M5 screw passes through
- 5.3–5.5 mm
- M3 nut trap (across flats 5.5 mm)
- 5.7–5.8 mm
- Magnet 6 × 3 mm
- 6.1–6.2 mm
- 608 bearing (22 mm)
- 22.1–22.2 mm
- Print-in-place moving parts
- 0.3–0.5 mm gap
Round holes print a bit smaller than drawn, especially small ones. Print a small test piece before a big part.
Gaps for press, snug and sliding fits, plus a hole calculator.
How to use
- 1Enter the size of the part that goes in.
- 2Pick the fit type and printer.
- 3Draw the hole with the size shown.
FAQ
- Why are my holes too small?
- Round holes print slightly undersized on FDM printers. Add 0.1–0.3 mm or use your slicer's hole compensation.