From FreeCAD Documentation
- The command can detect screw diameters automatically. Holes must have the correct diameter for this to work. For example an M5 screw requires a 5mm pass hole or a 4.2mm tap hole. The
Fasteners ScrewCalculator command can be used to determine tap hole diameters.
- Select a part with circular holes.
- There are several ways to invoke the command:
- Press the
Make countersunk button.
- Select the Fasteners →
Make countersunk option from the menu.
- The Chamfer holes for countersunk screws task panel opens.
- The Edges to chamfer list shows all circular edges of the selected part.
- Select the edges you want to chamfer by doing one of the following:
- Click individual circular edges or faces with circular edges in the 3D view:
- There is no need to hold down the Ctrl key.
- Each selected edge is checked in the Edges to chamfer list.
- The screw diameter for each edge is detected automatically.
- Edges cannot be deselected in the 3D view.
- Select or deselect edges by checking or unchecking them in the Edges to chamfer list:
- In this case the screw diameter is not detected automatically.
- Optionally change the screw diameter of individual edges in the Edges to chamfer list by double-clicking their Diameter field, and selecting a new value from the dropdown list that appears.
- Optionally change the screw diameter of all selected edges by selecting a new value from the Diameter dropdown list below the Edges to chamfer list.
- Optionally specify a Screw type.
- Press the OK button.
- A Countersunk object with a chamfered recess for each selected edge is created.
- Optionally attach screws. See Fasteners Workbench.