BoltGen with Manuals and help for Rhinoceros (Windows and MAC)
(by armac)
Create accurate Metric and English Bolts and Nuts in Rhinoceros
Support Email

BoltGen is a free Rhinoceros Plug-In that generates both Metric and English bolts and screws with nuts if desired.  It comes in several versions for Windows and one version for MAC computers.  In addition to generating bolts, other functions extend its usefulness.

Available Rhinoceros plugins: New Python versions of BoltGen and older Rhinoscript versions BoltGen and external program BoltGenGUI (Graphical User Interface available only on website below) are free programs that create accurate Metric and English machine bolts of any length.  In addition, BoltGen creates inside-thread-cutters (along with hex-nuts with and without threads).  Generated part Names (in Layers Properties window) allow easy identification.  Alternatively, the older BoltGenGUI provides an easy-to-use Graphical User Interface and runs external to Rhinoceros 5, but uses Rhinoceros 5 as a graphics engine.

 Screw head types include Sockethead Capscrews, Flat head Capscrews, Flat head Machine screws, Oval Heads, Pan heads, and Hex Heads, or just threads without heads if desired.

Head drives include Torx, Philips, Allen and Hex wrench if available for the screw type.

4 bolt styles can be created: threaded, without threads (reducing file size), and each as block instances (multiple copies of one item).

BoltGen is multilingual supporting English, Spanish, German, Czech, Italian, French and Chinese.

A second command BoltGenAN (in the older BoltGen plugin or in BoltGenGUI on the website below only)  is provided to make type AN Aircraft Bolts (with wire holes).

A New function Copy_Bolt_To_Surface copies a created bolt and reorients the bolt to surfaces (surface normals).  In Windows 5, multiple copies can be quickly done at a time by hitting RETURN key instead of selection box (OK mouse click) conviently sets up for a new placement.  Right-click or ESC key aborts placement.  (Windows 6 needs mouse-click menu selections to implement functions.)

For Rapid-Prototyping (create actual working parts), an additional Menu Dropdown function called ThreadCutterScaler is included to resize the XY values of a generated Inside_Thread_Cutter threaded rod.  It allows resizing the cutter (or any object center-referenced at 0,0) in the WorldXY plane to increase thread slop when using the Inside_Thread_Cutter in a boolean-difference function to cut inside threads in a solid (such as a nut).  Resizing is done by using a multiplier value.  Example: multiply by greater than 1 (ie. 1.01) to increase size, or less than 1 (ie. 0.99) to reduce size, and can be repeated as necessary.

Note:  Inside threads are slightly different than the screw threads.

For more free downloads:

To install:

Older Plugin version:  Download, unZip, and place BoltGen.rhp in Rhinoceros Plug-in Folder.  Right-click file, select Properties, and Unblock.  Start Rhinoceros, choose Tools, Options, Plug-Ins, and Install BoltGen.  Restart Rhinoceros.

New Python version: Download self-installer, double-click or drag to Rhino window.  Restart Rhinoceros. 


GUI version (from website below only): (does not have CopyBoltToSurface or Chinese support) Download, unZip into temporary folder, and execute setup.exe.  The BoltGenGUI program may be executed from your Start menu in folder BoltGen.  Program launches Rhinoceros if not already running (caution: if Rhino is launched, BoltGenGUI will also ask to close Rhinoceros upon exitting the program).  Please see the Read Me.txt file in the download for more information.


There is also version of BoltGen for MAC computers that is mostly functional.

  • BoltGen works except for sorting the directory at the end of creations (minor inconvenience)
  • ThreadCutterScaler works.
  • BoltGenHelp works.
  • CopyBoltToSurface is very buggy and is not reccommended.


All BoltGen versions and updates are also available at the McVan Aerospace website:


License Cost:
BoltGen for Windows 5 and 6. Python version 1.85
Rhino 5 for Win
Rhino 6 for Win
BoltGen for MAC Rhinoceros WIP. Python version 1.85
Rhino 6 Mac