How to Add Screws and Nuts in FreeCAD with Fasteners

This guide explains how to quickly insert and configure standard screws, bolts, and nuts in FreeCAD using the Fasteners Workbench. You will learn how to install the workbench, generate standard ISO or DIN hardware, adjust dimensional parameters like diameter and thread length, and accurately position fasteners onto existing 3D geometry.

1. Install the Fasteners Workbench

If you do not already have the Fasteners Workbench installed:

  1. Open FreeCAD and click on Tools in the top menu.
  2. Select Addon Manager.
  3. In the Workbenches tab, search for Fasteners.
  4. Click on Fasteners Workbench and click Install.
  5. Restart FreeCAD when prompted.

2. Switch to the Fasteners Workbench

Once installed, navigate to the workbench selector dropdown in the top toolbar (which usually defaults to Start or Part Design) and select Fasteners. The toolbar will update to display various categories of hardware, including hex bolts, socket head cap screws, countersunk screws, standard nuts, and washers.

3. Insert a Screw or Nut

  1. Ensure your active document is open.
  2. Click on the icon representing the type of fastener you need (for example, ISO 4762 Hexagon socket head cap screw or ISO 4032 Hexagon regular nut).
  3. The selected fastener will appear at the origin point (0, 0, 0) of your 3D space, and its label will appear in the Tree View on the left.

4. Adjust Fastener Dimensions and Properties

To change the size, length, or thread style of the fastener:

  1. Select the fastener object in the Tree View.
  2. Look at the Property panel in the lower-left corner (under the Data tab).
  3. Modify the core parameters:
    • diameter: Select the nominal thread size (e.g., M3, M4, M5).
    • length: Choose from standard predefined lengths (for screws and bolts).
    • thread: Set this to true if you need fully modeled real 3D threads, or keep it false for simplified threads (keeping it false improves system performance).

5. Attach Fasteners to Holes and Circular Edges

The Fasteners Workbench includes an automated attachment feature that places hardware directly onto a target hole:

  1. In your 3D model, select the circular edge of the hole where the screw head or nut should sit.
  2. Click the desired fastener icon from the toolbar. FreeCAD will automatically place the fastener aligned with the hole and set its diameter to match the hole size.
  3. If the screw is facing the wrong direction, select the fastener in the Tree View, go to the Data tab, and toggle the invert property to true.
  4. If you already created the fastener, you can select the hole's circular edge, hold Ctrl, select the fastener in the Tree View, and click the Move fastener to selected location tool in the Fasteners toolbar.