Morbias there not there for any safety reason, lots of manufactures use them i dont know why but have always assumed that there put on to keep the drums on in the manufacturing prosess to hold the drums on on the production line, some makes use a screw some use 2 torques bolts either way there a pain to remove for servicing the brakes, i can see why locating bolts are used when a cars wheels are secured with wheel bolts as this keeps the holes in line with the disk/drum with the hub