Characteristics of circular slitting blade in metal sheet slitting 1) Blade material: 9CrSi, GCr15, Cr12MoV, HSS, TC for different customers. 2) To the circular slitting blade, steel core, spacer with OD less than 200mm, their flatness and parallelism could be controlled within 2u, thickness could be within + -1µ.To those with OD over 200mm, their flatness and parallelism could be controlled within 2µ, thickness could be within + -1µ.