This is model of simple nutcracker.
To make part stronger I recomended to use 3 perimeters and 5 top and bottoms solid layers and at least 70% of infill.
Holes for M4 screws in lever should be tapped M4 thread.
Hardware needed.
-1x M6x60mm Socket Head Screw
-1x M6 Nylon Lock Nut
-2x Washer for M6 screw
-2x M4x16 or M4x20 Socket Head Screw

Material recomended: PET-G or stronger
Layer high: 0,3
Support needed
Infill at least 70%