Tolerance and clearance test for metric M3 and M6 bolt/screw, M3 nut, and printed pegs (hexagonal, circular, and square). Every 3D printer will have slightly different dimensional accuracy. This simple print can give you a lot of information about what dimensions will give you a tight fit, loose fit, or allow a bolt to thread easily into the plastic. I still occasionally pull it out of my drawer for reference.

The first column on the left is the base size:

• M3 3mm diameter circular hole
• M3 hex hole is exact dimensions of an M3 nut
• M6 6mm diameter circular hole
• 6mm wide square hole

Each printed peg is to exact dimensions:

• M3 hex
• M6 6mm diameter circular peg
• 6mm wide square peg

Each column from left to right adds 0.1mm to the width/diameter.