Forged stainless steel disc w/41 locking pins, 41 springs and 41 mtd stainless steel blades, 33.435 in. Min t0 33.441 in. Max od, tapered ctr bore 2.883 in. Min to 3.084 in. Max id w/2 keyways, 2.374 in. Min to 2.376 in. Max thk, for cw ratation, statically balanced