Hex head screws are also beneficial in predicaments where Room is restricted, as their exterior travel head doesn't call for just as much clearance as being a screwdriver or Phillips head would. On the ball screw, the nut and screw have matching helical grooves that let ball bearings to re-flow https://andywzazz.luwebs.com/29952227/types-of-screw-heads-chart-an-overview