I have the Suncast slat wall system in my garage and need to hang some tools that have some weight. Let's face it, we all know when you 3D print pegs they are only so strong even with high infills. So, I decided to use a metal bolt at an angle that would fit into a 3D printing that snaps into the slat system. It is designed for the Suncast slat wall sections which are sold by Home Depot and other home improvement centers.
https://www.suncast.com/sw04.html
https://www.suncast.com/sheds-storage/garage-storage/slat-wall-systems.html

Settings (Suggested)
Raft: On
Supports: On
Infill: 35% Suggested to make sure 'pegs' are strong.
Shells: 3
Layer Height: 0.20mm
After printing,clean up and remove raft and supports with an xacto knife. Be careful not to damage pegs during cleaning. File as necessary for good fit in slat board. Ream the hole with a 6mm drill for the bolt. The hole is at 10° angle. I used a 6mm x 40mm bolt with a 10mm hex head. Insert bolt from backside. The hex head should fit snugly. Use a 6mm nut to tighten on the front side.This is very strong and can hold some very heavy tools.