I first made the wooden version of this hook. I thought this is a nice 3D project, too.
It has 2 parts that are symmetrical. My model is for a 1,5" Pipe (inner diameter 39mm) and M6 screws. So you have to print 2 of them.
The alternative model is for M4 screws has 10 pins, just as example how the OpenSCAD model can be used to create hooks with other dimensions.
The author marked this model as their own original creation.