Try This Instead

Try out my elastic band peg - it's print-in-place design uses an elastic band for grip and is configured with different mounting options! https://www.thingiverse.com/thing:4398327

It works much better if using a material that is unable to retain it's spring tension with repeated use as is common with PLA.

Show Rail Peg

This is single part peg with integrated hook to suit a 20mm Ø shower rail for hanging your towels or other items. I printed this PLA+ at 0.2mm with 100% infill. You could easily print this in whatever material suits you as it's a very simple design.

I've provided the Fusion 360 file so you can edit the hook to suit your rail diameter.

http://www.samjohnston.net/blog/2018/9/15/shower-rail-peg