T-Nut / C-Nut Block fully customizable M5 / M6

When converting my workshop from French Cleat to C-slot profiles, the need arose to create sliders for the profile into which a nut can be inserted and a screw turned in, or a screw inserted directly.

Since these blocks generally also fit into 4040 extrusion profiles, but many profiles have their own dimensions, the idea came up to make the 3D print file completely customizable. With this model, you can freely configure what you need for your profile.

Explanation of Parameters

1. Mx
   • Description: Selection of thread type.
   • Values:
     • 5 → M5 thread
     • 6 → M6 thread
   • Effect: Determines the wrench size (AF), nut height, and drill diameter.
2. WIDTH
   • Description: Overall width of the clamping surface and the upper foot edge.
   • Default value: 16 mm
   • Effect: Influences the stability and contact surface of the T-nut block.
3. GUIDE_WIDTH
   • Description: Width of the upper guide web (“hat”).
   • Default value: 8 mm
   • Effect: Adjusts the guide for the groove.
4. GUIDE_HEIGHT
   • Description: Height of the guide web.
   • Default value: 4 mm
   • Effect: Determines how deep the T-nut block sits in the groove.
5. CLAMP_HEIGHT
   • Description: Height of the clamping surface (middle area).
   • Default value: 3 mm
   • Effect: Influences the overall height and clamping force.
6. FOOT_HEIGHT
   • Description: Height of the trapezoidal foot.
   • Default value: 3.5 mm
   • Effect: Determines the taper of the foot (45° angle).
7. LENGTH
   • Description: Length of the T-nut block along the Y-axis.
   • Default value: 20 mm
   • Effect: Adjusts the length for various groove sizes.

Automatically Calculated Dimensions

• hex_af(Mx): Wrench size of the nut (8 mm for M5, 10 mm for M6).
• hex_h(Mx): Height of the nut (4 mm for M5, 5 mm for M6).
• clr_d(Mx): Through hole (5.5 mm for M5, 6.6 mm for M6).
• hex_outer(Mx): Circumference diameter for the hexagonal pocket (AF / cos(30°)), so that the wrench size is exactly correct.