A Stronger Bolt

This is not so much a remix or new "thing". It's more of an idea.

I have been using the excellent Nut_Job OpenScad program to make some nuts and bolts. They print great. However my application puts some lateral stress on the bolts and they snap quite easily along the layers. How can I make it stronger?

I played around with different temperatures and fan settings. I can get the bolt quite strong using PLA at a higher temperature with no fan (to get the highest possible inter layer bond