RING GEAR - 1050 STEEL / HEAT TREATED Heat treated for durability. The gears are heated then pressed on and secured with grade 8 button screws. REPLACEABLE FRICTION PLATE - 1045 STEEL The friction surface Fidanza use is an incredibly strong 1045 steel. The plates are milled to meet Fidanza's high specifications. With these replaceable plates there is no need to replace the entire flywheel when the clutch or flywheel is at the end of its life, saving time and money. BUTTON SCREWS - GRADE 8 Increased security helping fasten the ring gear to the flywheel. FASTENERS - MILITARY SPEC Military grade aerospace fasteners aid in pulling heat away from the clutch face. Properly spaced for form and function. STEPPED DOWELS - STEEL Once pressure plate is installed they become locked in place. First in the industry to implement the use of stepped dowels. Flywheel weighs 14.45 lbs for 3.5L