There has been a definite change in the types of scrap being shredded these days. We are seeing much lighter scrap as everyone who has a shredder has noticed and more non-metallics. The old days of 15 to 20% loss in white goods and 25 to 30% loss in autos are long gone. Baled sheet metal is more common as shredders reach further out for material. More powerful balers generate hard hitting bundles that test your hammers and keep the motor working hard.
So which kind of hammers should you use?
Manganese steel hammers basically have been around since the shredder was invented. Manganese is still the hammer of choice for the vast majority of shredders around the world. It is usually the lowest cost per processed ton performer and the most forgiving with baled and heavy scrap. If your product mix has a good percentage of heavier scrap to shred, you will be able to work harden the hammers for excellent wear. For best results, manganese hammers should have a minimum 1/2% Molybdenum (moly).
Alloy steel hammers, both UHT and DHT types are up and coming products targeting the shredders with lighter gauge scrap to process. Be sure you compare the higher costs of the alloy hammers versus the increased tons of processed material. For instance, if you are getting an additional 50% increase in tons out per set, and you are paying almost double the cost, does it make sense for your operation? Even with the labor savings from delayed hammer changes, you may still save money with manganese.
Forged hammers are the newest and most expensive type in the market today. They are a hard hammer, so you will need to have special hammer pins as well. Otherwise you will wear your normal pins out much sooner. Monitor it closely to see if your cost to shred comes down as much as you anticipated. We are hearing double or more the wear life compared to manganese. Gather all costs, so you can compare the hammer cost per ton with pins included. While an improvement, it may not be as much a savings as anticipated. Only your numbers will lead to the right answer.
K2 Castings produces manganese and alloy hammers for all sizes of shredders. Our suggestion is to test them both and settle on the type which works better for your product mix. If you have any questions or need some help figuring out which is the most cost effective for you, let us know. We will be happy to help you out.