Gravity Boxes Unverferth Grain Handling

Some producers think all gravity boxes are the same and are only for hauling grain. Unverferth gravity boxes, however, are much more. We design and build them for transporting all kinds of bulk items such as feed, seed, and fertilizer.  Match your desired capacity gravity box with an appropriate size Unverferth running gear and you'll have a gravity wagon assembly to help you get the job done.  Plus, you can add an optional Unverferth unloading auger or conveyor for even more versatility.

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Gravity Box

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Models & Capacities

Models 325 and 235 feature a single compartment and standard capacities of 255 bushels and 190 bushels respectively.  Optional 24” sideboards bring the total capacity on model 325 to 400 bushels and 310 bushels on model 235.  Optional 20” sideboards allow the model 325 to fit 375 bushels while the 235 can carry 290 bushels.  On model 235, 15” sideboards can be added for a total capacity of 265 bushels.

UM Model 325 Overall


A low center of gravity and balanced weight distribution provide stable towing while the rugged continuous-bead MIG welding and one-piece door and side panel enhance sidewall strength and durability.


The rack-and-pinion mechanism for the wheel-operated unloading door permits easy opening, even with a full load of high moisture grain.  An optional deflector chute is available to permit center-unloading.

Model 325 features dual side-viewing windows and a sampling door within the main unloading door for convenient moisture and quality testing.

Unloading is fast and complete with steep-sloped sides and a graphite-coated interior.

Gravity Wagon Viewing Ladder

Additional Features

A front-mounted ladder is standard for easily viewing the hopper contents; a rear-mounted, five-rung ladder is optional.

A full primer undercoat and durable high-quality equipment enamel topcoat of red or green for a long-lasting finish and all exposed seams are silicone-sealed for corrosion resistance.  Rounded box corners protect the optional tarp against punctures and tears.

Model 325 Rear View

Transport Lights

When ordering an Unverferth gravity box with an Unverferth running gear, the gravity wagon assembly comes standard with red and amber taillights for transport safety.  This transport light kit is optional on gravity boxes ordered by themselves.

Gravity Wagon Tarp

Optional Tarps

Choose an optionally fitted tarp for an economical design or equip your model 325 with a deluxe rollover tarp that provides a quick and easy covering of the wagon's contents.


Model No. GB 325 GB 235
Approx. Bushel Capacity 400 375 255 310 290 265 190

*Divider is shipped loose

Due to continuing improvements in the design and manufacture of Unverferth products, all specifications contained herein are subject to change without notice.

Extension Size 24", 4- side 20", 4- side -- 24", 4- side 20", 4- side 15", 4- side --
Inside Length 12' 10'
Inside Width 7' 6" 7'
Transport Height - Mounted 9'4" 9' 7'4" 9'2" 8'10" 8'5" 7'2"
Transport Width 8' 7'4"
Number of Doors 1 1
Door 20" x 34 1/2" 20" x 25"
Approx. Weight 1760 1720 1460 1500 1356 1308 1110
Running Gear RGE-13 or RGEB-13 RGE-10 or RGEB-13 RGE-1202 RGS-10 or RGE-10 RGS-8 or RGE-8