It's preferable to use with a press but there is a hole for a 12mm bolt. When using the bolt method a regular sized washer is recommended on the male part and a large thick washer (37-47mm) on the female part.

100% infill is recommended but also works down to about 50% infill with a few mm thick walls. Has been tested on up to 1.5mm steel and 3mm aluminium sheets without issue with 100% infill. No support needed for the lettering on the side.

I added information on side of the model to show what size the tool is and changed the diameter of the bolt hole to accommodate metric hardware. Also provided separate files for the two parts incase only one needs to be replaced etc.