Metal shredders are machines widely used in scrap yards or metal recycling plants to shred the metal scraps into smaller shapes and sizes. It mainly consists of shredder housing, rotor and hammers. As the feed is metal or steel objects, the hammers have to withstand extremely harsh scratch and also impact force from the scraps. The hammer must have good strength at the handle area to provide good impact resistance for hammer, and in the mean time good wear resistance is required at the wear areas.