Below is a general manufacturer product group description. Please note the information below is not item specific. Item specifics are above in product details.

Fidanza Aluminum Flywheels are made from the highest quality 6061 T6 aluminum. The material is fantastic for strength, heat dissipation and of course reduction in weight.
The friction surface used is an incredibly strong 1045 steel. The flywheel friction plates are milled to meet extremely high specifications. A Fidanza aluminum flywheel can mate with any type of clutch material, including organic, kevlar, ceramic, metallic and sintered iron. The replaceable friction surface is attached with military grade aerospace fasteners. With these replaceable friction plates there is no need to replace the entire flywheel when the clutch or flywheel is at the end of it’s life, saving time and money. The ring gears used are also made from 1050 steel and are heat treated for durability. The flywheel ring gears are heated then pressed on and secured with grade 8 button screws. Fidanza was the first to utilize a stepped dowel system in most of our flywheel applications. This doweling method ensures that once the pressure plate is installed the dowels cannot be removed because they become locked into place.
No chromemoly can compete with the awesome serviceablity, strength and superior design of Fidanza’s aluminum flywheels. If there was a better material out there, we would be using it.