Cutting Cylinder blades are manufactured from high carbon-boron alloy steel and then hardened to RC46-49 to match the temper of our bedknives and original equipment bedknives. All R&R Reels are cylindrically ground on bearing surfaces and then relief ground. Reels are then precision computer balanced for extended bearing and reel life. TMS Reels are guaranteed against defects in material and workmanship for the life of the reel under normal use.