Steel wire is used to reinforce these 3D printed hooks. Budiul printed the hooks in two halves with a cavity for the wire, then used acetone to glue the parts together. The result is a much strong hook for the tool wall.
See the project page:
This is an entry in the Repairs You Can Print contest:
Read the article:
Repairs You Can Print: Fixing Pegboard Clips That Break Too Easily
Brilliant path to stronger wall hooks through 3D printing with reinfocement