This high speed abrasive roll mandrel is 6" long with a 1/4" shank. The 1/8" diameter pilot is 1" long. For best results use this and all Abrasive Roll Mandrels with light side pressure to avoid bending. For a smoother cut & longer abrasive life use Grinders Grease. Always wear appropriate face and hand protection when using this product. This high-speed mandrel is intentionally unhardened, such that it will resist shattering when fatigued. Excessive side-loading or use with unbalanced abrasives may cause mandrel to bend or break. Periodically check mandrel for bending, and if found discard immediately. When using with cartridge roll abrasives, allow the abrasive to do the work (do not apply excessive pressure). For larger diameter (3/4" and greater) rolls, reduce operating RPM to 12,000 maximum. Replace any cartridge roll that delaminates or becomes imbalanced.