Screw Generator by Koolm
Metric and inch screws, nuts and washers with real thread specs, made on MakerWorld
Opens makerworld.com
About Screw Generator by Koolm
Koolm's Screw Generator is the most liked fastener tool on MakerWorld, with over 150,000 customizations, and it was featured on Hackaday in early 2025. It is an OpenSCAD script built on the BOSL2 library, wrapped in MakerWorld's form-based customizer so you never see the code.
Pick a screw, nut or washer, then choose the size: metric M2 to M24 or UTS inch sizes from #4 to 7/8 inch. Screws can have hex, pan, flat, socket and other heads, with Phillips, Torx, slot and other drives, and you set the length and thread options. The geometry follows ISO, DIN and UTS dimensions, so a printed nut can fit a real bolt and the other way round, within the limits of your printer.
It is free with a MakerWorld account and downloads as STL or 3MF. It suits repairs, prototypes and anyone who needs an odd fastener tonight rather than next week. Printed threads are no match for steel, so keep loads light.
What you can make
- Screws and bolts
- Nuts
- Washers
How to use it
- Click Customize on the model page
- Choose screw, nut or washer and the size
- Set length, head and drive type
- Generate and download
Good
- Real ISO/DIN and UTS dimensions
- Wide choice of heads and drives
- Very popular and well tested by the community
Not so good
- Printed threads are far weaker than metal ones
- Needs a MakerWorld account
What you'll need to print it
Materials and parts that give the best results with Screw Generator by Koolm.
PETG for functional and outdoor prints
PETG handles heat, sunlight and repeated flexing better than PLA, so Gridfinity bins in a hot garage or signs mounted outdoors keep their shape.
- Bambu Lab PETG BasicUpgraded formula that Bambu says matches PLA Basic for strength while staying impact-tough; low price per spool in multi-roll bundles.
- Polymaker PETGHigh-flow replacement for PolyLite PETG: strong, low-odour and quick to print.
- Overture High Speed PETGGood-value PETG in a large colour range for functional parts in bulk.
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