I wanted to create a cleat so that I could tie a thin rope off in my workshop and found this one: https://www.thingiverse.com/thing:2298763. I liked the simple design but I wanted one that would fit standard chipboard screws so I whipped up my own version in Fusion360 - I've included the file in case you want to adjust the dimensions for yourself - the main ones are in the parameter settings.
The dimensions I have used are 12mm wide X 70mm long x 17mm high.
I printed it in PLA at 100% infill with several perimeters to give it plenty of strength.
The author marked this model as their own original creation.