... Production material :65Mn(65Mn Spring steel). 2. The range thick is 2-3mm. 3. Hardness:48 ... . Production material :65Mn(65Mn Spring steel).2. The range thick is 2-3mm.3. Hardness:48-584 ... varnish,blacking,zinc galvanized,plastic spray.From the processing craft,the harvetser blade includes rolling and milling teeth ... ensilage cutter ,fodder disintegrator , spade head / plowshares of the planting machine.