The set screw is a straight blade screw, not a hex screw. The bit has a flat side where this screw needs to be tightened, but there's no way of knowing if you're tightening on the flat or in between, etc. If it's not tightened, the screw will quickly loosen and fly out of the shank , lost forever and no additions included in the pack. A set of hex bolts from Port Freight did not have the correct thread size, so this unit is now unusable. The quick release feature is pretty cool, but I foundβ¦