M8 Zinc Bolts and self locking nuts

My order of 150 nuts and bolts have arrived. I tried to find bolts that used allen keys, but they were drastically more expensive. Instead, I looked for bolts that were only partially threaded, which should give more usable life than if the bearings were pressing on threads.

[first bolts I bought on left, new in centre, bearing location on the screw is simulated on the right]