Screw M4 Allen Cylinder Head, length 30 mm or more
Instructions
For extra strength set your slicer to use more perimeters (e.g. 3).
For extra strength use some stronger infill pattern as honeycomb or triangles, 25% infill.
Put M4 nut into the pocket.
Use a M4 screw of sufficient length.
The end cap is optional if you do not want to damage the clamped part.
Source file
You can also download source file for FreeCAD which contains both models (clamp + pad) and in the Dimension table you can specify your own clamp length (inner dimension).
Pomi
