Made In USA. Melling recommends new rocker arm studs with every engine rebuild. Old studs are subject to metal failure, stud stretching, and worn threads. Studs also tend to be lost or damaged during the rebuilding process. There is also a danger of metal cracking when the old rocker arm stud is removed from the head. Melling rocker arm studs are manufactured to high quality and material standards. Using new rocker arm studs assures proper installation and valve train adjustment.