I have added nut place on the handle. The nut is standart with thread M6x1. The bolt is awlso have thread M6x1 - 25mm. long without the bolt head. And I've made cavities and holes to reinforce and save material. I widened the handle a little bit to make it stronger. Everything is visible in the pictures.
P.S. No supports needed at all.
any ABS or PLA
zigzag 50% (2 mm. wall (skin) It is imortant!!!)
PLA is better in this case.
If print it from ABS use brim build plate adhesion.