These ball socket thumb screws have round or flat ball at the contact end. The flat style is excellent for supporting a soft workpiece, exerting a clamping force or supporting a workpiece at an angle. The ball rotates in the screw socket as force is applied allowing contact to be maintained on moving or contoured surfaces as force is applied. The screw is made from heat-treated 4135 steel with a black oxide finish. The ball is made from heat-treated steel.