The choice of many top professional engine builders for their all-out competition power plants. Manufactured from a premium grade 8740 alloy that is heat-treated to 200, 000 psi, which is considerably stronger than Grade 8 hardware. Kit comes complete with premium quality parallel ground washers and compact 12-point style nuts. 1000% better fatigue strength than many other studs. Centerless ground to be as perfectly concentric as possible.