A tub grinder is a heavy-duty agricultural machine that uses a rotating tub, hammermill, and interchangeable screens to reduce hay bales, straw, grain, wood, and biomass into precisely sized particles. Farmers, feedlot operators, and biomass processors worldwide rely on tub grinders to turn raw material into consistent, high-value feed and fuel.
At its core, a tub grinder is simple: material goes in whole, comes out chopped to a precise, controlled size. But the engineering behind that simplicity is what separates a real grinder from a shredder.
A large, rotating steel tub sits on top of the machine. You load whole bales, logs, or loose material directly into it. As the tub rotates, it feeds material down into the hammermill at a controlled rate. The tub’s size directly determines how much material you can process continuously. Bigger tub, bigger bite, more throughput per hour.
Below the tub, a high-speed rotor spins forged steel hammers at tremendous velocity. These hammers shatter, tear, and reduce whatever the tub feeds down. The number of hammers matters: more hammers means more contact points per revolution, finer grinding, and higher throughput. HayBuster tub grinders use 64 to 88 forged hammers depending on the model.
Beneath the hammermill, an interchangeable screen acts as a gate. Material stays in the grinding chamber until it is small enough to pass through the screen openings. Swap the screen, change the particle size. From 1.5 mm for fine grain to 500 mm for coarse wood chips, the screen gives you total control over your output.
Why particle size matters: University research confirms that correct, consistent particle size in TMR (total mixed ration) drives higher dry matter intake in cattle. In one study, cows fed processed 2-inch straw ate 1.43 kg/day more than cows fed 7-inch unprocessed straw, and maintained better body condition with less feed sorting.
The word “hay” is in the name, but tub grinders handle far more than hay. Modern tub grinders process nearly any dry or semi-dry organic material.
Round bales, large square bales, small squares. Alfalfa, grass hay, wheat straw, oat straw. The core application for TMR dairy and beef feeding.
Corn, wheat, barley, sorghum, and all cereals. With a grain hopper accessory, the hammermill processes grain at full capacity using electronic governor control.
Pallets, stumps, land-clearing brush, orchard prunings. DuraTech tub grinders were built for exactly this: the heavy-duty work that pushed beyond agricultural applications.
Corn stover, rice straw, sugar cane trash, energy crops, manure-mixed substrates. Tub grinders prepare feedstock for anaerobic digesters and biomass boilers worldwide.
Material up to 30% moisture can be processed, with reduced throughput. Rear-mill designs like the H-1030 handle wet material with less jamming.
Straw processed to short, uniform lengths for livestock bedding. Consistent particle size means better absorption and cleaner stalls.
HayBuster was born in 1966 in Jamestown, North Dakota. The original machines were built for one job: grinding hay bales into feed for cattle. Ranchers across the Great Plains needed a reliable way to process round and square bales into consistent TMR feed, and HayBuster delivered.
But farmers are resourceful. They started putting heavier, tougher materials into their HayBuster grinders: brush from fence lines, wood waste from old buildings, stumps from land clearing. The machines could handle some of it, but the demand kept growing for something stronger.
That is why DuraTech Industries was created. DuraTech became the parent manufacturer, building not just the agricultural HayBuster line but also a new class of heavy-duty industrial grinders. Where HayBuster models carry the “H” prefix (H-835, H-1000, H-1030, H-1135, H-1155), DuraTech’s industrial line carries the “HD” designation: the HD-1000 for heavy-duty wood and demolition waste, and the massive 3010T and 6010T industrial grinders used by municipal waste processors and biomass energy plants.
H vs. HD: The “H” in HayBuster models stands for the original agricultural heritage. The “HD” in DuraTech models means heavy duty. Same factory, same engineering DNA in Jamestown, ND. The HayBuster line is purpose-built for agricultural grinding: hay, straw, grain, and biomass. The DuraTech HD line handles the materials that go beyond agriculture: construction debris, pallets, stumps, and industrial waste streams.
Today, DuraTech Industries manufactures both lines from the same factory in Jamestown. Every HayBuster tub grinder benefits from six decades of engineering refinement, including the heavy-duty lessons learned from DuraTech’s industrial machines. Forged hammers, precision screens, and rugged drivetrains trace a direct line from those original 1966 hay grinders to the current H-1155 flagship.
Tub grinders range from compact PTO-driven units to massive electric-powered machines. The right choice depends on what you are grinding, how much moisture it carries, and how many tonnes per hour you need.
The entry point. Requires 100 to 150 HP tractor. Handles hay, straw, and grain on small to mid-size operations. Available with electric drive for indoor or biogas facility use. Three H-835 units fit in a single 40-foot shipping container.
The best-value machine in the line. Front-mounted mill with 64 forged hammers. Ideal for dry material under 20% moisture: hay bales, straw, alfalfa, grain. Two H-1000 units ship in a single 40-foot container.
Rear-mounted mill gives more clearance around the screen area, reducing jams with high-moisture material. Tilting tub for easier cleanout. The preferred choice for humid climates, manure-mixed substrates, and tropical crops like sugar cane trash and rice straw.
The flagships. 88 forged hammers deliver maximum throughput. The H-1135 is available in both PTO and electric (H-1135E) configurations. These machines serve large-scale feedlots, industrial biogas plants, and biomass energy operations across six continents.
Not sure which one? Use our Which HayBuster guide or request a quote with your material type and volume. We will recommend the right machine for your operation.
From a single hay grinder in North Dakota to six continents and counting. Tell us what you need to grind, and we will match you with the right machine.
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