Steel rotors have applications in all types of motorsports. Steel rotors provide a durable lightweight option in applications where sustained temperatures remain in the low to moderate range, and high heat spikes are only observed on an intermittent basis. This could be anything from a hard stopping drag race car at the end of a quarter mile, or a high speed stock car coming in from a qualifier at a super speedway. Steel rotors can also be found in lighter weight open wheel cars such as sprints and modifieds, and a variety of light weight, open wheel road course racers. a special alloy and proprietary manufacturing processes give these rotors high resistance to thermal distortion with excellent friction and wear characteristics against the pads. Dynamic mounting is the most effective method of eliminating all types of thermal stress and distortion in steel rotor applications. These rotors are machined with mounting slots that are used with special t-nuts and bolt kits. This mounting system allows the rotor to expand and contract independently of the mounting hat or hub as the rotor goes through temperature changes. This eliminates all strain or bind at the mounting points. The rotors run truer, last longer, and all undue stress on the hats or hubs is eliminated. Dynamic mounting is preferred in all applications where temporary, but extreme temperature spikes may cause high expansion rates in the steel. Wilwood also offers slotted dynamic mount hats and plates that are used to provide the "float" with a standard hole mount rotor, but the rotors in this category are machined for use on " fixed" mounts that require the "float" to be placed within the rotor itself.Pit Stop USA offers Wilwood Drilled Steel Scalloped Dynamic Mount Rotor - 12.19" Diameter - .35" Width - 8X7.00" Bolt Circle - Slot Hole Type - 6.56" Lug I.D. - 4.8 lbs. 160-5538 at low everyday prices. Be sure to check out all of our products from Wilwood Engineering including Wilwood Engineering Drilled Steel Dynamic Mount Rotors.