ACS designs and manufactures our own products. Our race series studs are heat-treated 8740 chrome moly. They have a tensile strength of 190,000 psi and are able to easily handle the acceleration shock loads (shear) and lateral forces (elongation)found in racing. We have our race & pro series fasteners tested to 190,000psi @ 40 Rockwell C which far exceed the commercial hardware specs of Grade 8 or 10.9. In fact they exceed the DIN 12.9 spec of 180,000 PSI.