The PST Drag Shaft is specifically engineered for your exact application. Horse Power, RPM, length of shaft, and Critical speed are all taken into consideration when deciding the proper shaft selection. The 1020 steel Drawn Over Mandrel (DOM) is a basic shaft that will suit many applications. For Horse Power over 1000 the Chromoly shaft is very strong. The Lightweight choice is Aluminum in both our Sportsman shaft and the full Drag shaft. The “Critical Link” Carbon fiber racing shaft is the industry standard in light weight, high strength, and safe shafts. Every shaft that we recommend is backed by PST, 100% against failure and workmanship. Please review the selections of your choice, and feel free to contact us with any questions or concerns.