Screw Generator for 3D Printing

Output

Fills diameter, pitch, head, nut, and washer with the ISO values for this size.

mm
mm

ISO 68-1 V-profile for standard fasteners.

mm
mm
mm

mm
mm
mm
mm

mm
mm
mm

mm
mm
mm

Part size: M6 × 16 mmGrid 5 mm · section 25 mm
Exact preview
Diameter D6 mmPitch P1 mmDepth0.54 mmCore ⌀4.92 mmHeight22.0 mmHeadSocketWidth across flats10 mmOuter Ø12 mm

Guide

Screw Generator for 3D Printing

Create a threaded rod or screw, a matching nut and a washer with dimensions you can change independently. Choose a metric preset or enter a custom diameter and pitch, preview the selected parts, and download their STL files. Use this editor for custom printed fasteners and mechanism prototypes where the thread geometry needs to match your design.

What the settings control

Diameter and pitch
Diameter is the nominal outer thread diameter in millimeters. Pitch is the axial spacing between adjacent thread crests. A metric preset fills the available dimensions, which you can then edit.
Profile, starts and handedness
Choose triangular, trapezoidal, ACME, buttress or square geometry. Starts changes the number of intertwined helices. Left-handed reverses the thread direction; keep matching parts consistent.
Head and drive
Use no head for a rod, or select one of the available head shapes. Head diameter, head height and drive dimensions remain editable. A drive that is too large or deep can leave insufficient material.
Undersize and nut clearance
Undersize reduces the rod diameter. Nut clearance adjusts the internal thread fit. They are separate controls, so change one at a time when diagnosing a tight printed pair.
Nut and washer
Set nut shape, width and thickness separately from the washer inside diameter, outside diameter and height. A washer opening should clear the actual screw that passes through it.

Starting example: the M6 coarse preset

Choose M6 with coarse pitch to start from a nominal 6 mm diameter and 1 mm pitch. With one start, the thread advances 1 mm per revolution. Select the rod, nut or washer to inspect that part on its own. This is a reproducible starting configuration, not a claim that an unadjusted print will fit commercial M6 hardware.

  • Diameter 6 mm, pitch 1 mm, triangular profile, one start, right-handed.
  • Example length 16 mm. Select a socket head and check its drive dimensions.
  • Keep the existing fit values for the first trial and record them before making changes.
  • Inspect the nut thread and screw separately in the slicer before printing a short test pair.

From settings to a first print

  1. Choose the part or set you want to create, then select a metric preset or enter a custom diameter and pitch.
  2. Set profile, starts and handedness. For a mating screw and nut, preserve those thread settings while changing the outer shapes.
  3. Adjust the head, drive, nut and washer as needed. Resolve editor errors such as an oversized drive or a nut wall that is too thin.
  4. Download the selected parts, inspect their slice preview and test the fit. Save a version before changing undersize or clearance so the next trial has a clear comparison.

Pitch and lead are different settings

Lead is travel per revolution. It equals pitch multiplied by the number of starts. A 2 mm pitch with two starts therefore gives 4 mm of travel per revolution; changing the starts does not turn it into a single-start 4 mm-pitch thread.

The editor uses millimeters for pitch. If your drawing specifies threads per inch, convert first: pitch in millimeters = 25.4 / TPI. Converting pitch alone does not establish compatibility with a particular inch-thread standard.

Reference: Thomson: the difference between screw pitch and lead.

Tune the fit with a short test pair

Nominal dimensions describe the model. The printed fit also depends on the manufacturing process, so use a short screw and nut before printing a long rod. Change one fit control, keep the same material and slicer settings, and record whether the pair starts, turns through its engagement and holds the intended position.

Clearance has no universal value across printers and materials. The STL also carries no tested strength or load rating. Treat a working hand-turned fit as a fit result, not as evidence of structural performance.

Reference: Prusa: designing printable features and fitting parts.

Frequently asked questions

Can I generate only a nut or a washer?

Yes. The part selector offers the complete set, rod, nut and washer. Select a single part when you want to preview and export only that component.

Are coarse and fine metric pitches available?

Metric presets include coarse pitch and the fine-pitch option stored for that size. You can also enter a custom pitch. Check the pitch value after changing presets instead of assuming it stayed the same.

Does the profile name certify a standard thread?

No. The profile selects the generated cross-section. Compatibility also depends on diameter, pitch, fit and manufacturing accuracy. Verify mating hardware dimensions and test the actual parts.

Should I scale an STL to loosen the thread?

Use the geometry controls to make a controlled fit adjustment. Uniformly scaling the whole STL changes pitch, length, head and other dimensions together, so it can change more than the intended clearance.