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Gravity Box Main Image
Gravity Box

The MK Gravity Box comes in three models, available with optional extensions. Ranging from 270-745 bushel capacities, we have the perfect sized Gravity Box for your operation.

Available on the proven running gear from Horst Wagons, or as a box-only model to place on your own wagon, you can rest easy knowing that the MK Martin Gravity Box is going to get your load where it needs to go.

Model MK 3200 MK 5000 MK 6500 MKGW12000
Extension N/A 8" 19" N/A 8" 12" N/A 8" 12" N/A
Capacity (Bushels) 320 375 450 500 570 605 645 745 800 1,200
Hopper Construction 14 GA. 12 GA. 12 GA. 12 GA.
Under Structure 3" x 6" x .188 wall rectangular tube 4" x 8"
.188" wall rectangular tubing
4" x 8"
.188" wall rectangular tubing
Unloading Door 45" width 57" width (standard)
28" width x2 (divider)
57" width (standard)
28" width x2 (divider)
15" length x 47" width X 2
Chute Height 17"-20" 17"-21" 16"-20" 18"
Box Dimensions
Length 158" 158" 158" 196" 196" 196" 229" 229" 229" 315"
Width 96" 96" 96" 101" 101" 101" 115" 115" 115" 110"
Height (less wagon) 78" 86" 98" 89" 98" 101" 91" 99" 103" 136"
Height (wagon & 22.5" wheel) 102" 110" 122" 123" 131" 135" 125" 133" 137" 156"
Weight (LBS.) 1,980 2,130 2,270 3,610 3,845 3,915 4,645 4,915 5,005 17,500
Wheel Base 112" 142" 156" 215"
Suggested Wagon 275 Horst Wagon - 425/22.5 Tires 365 Horst Wagon - 425/22.5 Tires 485 Horst Wagon - 425/22.5 Tires 608 Horst Wagon- 425/22.5 Tires (with brakes)
Unloading Door Feature Image

Unloading Door

Each Gravity Box comes with an easy to use unloading door equipped with a metering door, providing a smoother, more consistent flow of material. It also allows you to fine tune the amount of material leaving the Gravity Box ensuring that you're in control of the flow every time.

Front Ladder Feature Image

Front Ladder

The front ladder has a slightly angled incline for easier climbing, allowing you to look inside the Gravity Box with less effort and more stability.

Grain Shield Tarp Kit Feature Image

Optional Grain Shield Tarp Kit

The Grain Shield Tarp Kit is an option for all of the Gravity Box sizes. This ratchet-free locking system not only protects the contents from blowing away and from inclement weather, but also locks quickly and easily so you can head out sooner.

Road Lights Feature Image

Road Lights

Every Gravity Box comes equipped with road lights for safer road travel.

Sight Windows Feature Image

Sight Windows

Conveniently located beside the unloading door, these viewing windows allow you to see the current level of material inside the Gravity Box.

Divider Kit Feature Image

Optional Divider Kit

The optional divider splits your Gravity Box, allowing for two separate commodities to be in the box at the same time. Each side also has it's own door for individual unloading and metering.

Currently available only on 5000 and 6500 models.

Hydraulic Door Opener Feature Image

Optional Hydraulic Door Opener

The Hydraulic Door allows you to conveniently control the metering of the material using a remote from your tractor.

Currently available only on 5000 and 6500 models.

Extension Kit Feature Image

Optional Extension Kit

Available on all models, the optional extension kits increase the capacity of your MK Martin Gravity Box decreasing the amount of trips you need to make.

Optional Rear Ladder Feature Image

Optional Rear Ladder

The optional rear ladder gives another access point for operators to look into the Gravity Box.