Summary

To mount the the handle, heat up the scraper in your kitchen then just press it into the hole. Be careful because it will deviate.
The hole is about 1.5mm.

About the infill, you'll have to know wich use you are going to do, the more infill, the more strong it will be.
I was trying to take out some cork pasted to the floor, and I already splited the handle in half. It was a tough work.