This little hook is designed to be simple to print and lightweight yet still very useful.

If your radiator looks at least similar to mine, it will likely fit.

Second model also has an extra round hole of 22mm diameter modeled to it, which tightly fits around an old broom stick that i originally wanted to throw away. By using two of these i created an extra place for towels and such to hang next to the radiator.

HOW TO PRINT:

Make sure you have enough perimeters to cover the entire width. That's it. It's a speedy print.

If the dimensions don't fit your case, consider using XY or Z scale in your slicer.

For use on a radiator, consider not using PLA as with a radiator on full heat, it might warp. 

I personally printed this in ABS.