Headed Shear Connectors, also known as Headed Weld Studs, are used in all types of concrete connections. They can be welded to a flat surface or to the inside or outside of an angle.
Headed Shear Connectors come in diameters of 3/4", 7/8", and 1". See "Headed Concrete Anchors" for 5/8" diameter and below.
They are made of low carbon steel, ASTM A29, 1010-1020.