While an older flathead screw resembles a minus sign, the four-point plus shape of the Phillips provides more surface area to grip and turn the fastener.

This intentional slipping is called "camming out." It prevents the driver from over-tightening, which could otherwise strip the screw head or damage the workpiece.

Unlike older flathead drivers that frequently slide sideways off the screw, the angled edges of the cross shape naturally guide the tool directly into the center.

Because the screw naturally centered itself and slipped out before breaking, assembly lines could safely speed up vehicle production using motorized torque drivers.