Pro-Force Dry Fertilizer Spreader

The Unverferth Pro-Force dry fertilizer spreader features larger carrying capacities for fewer stops to fill, unrivaled spreading accuracy and consistency, and a wide range of options, such as an ISOBUS scale package and tracked undercarriage for greater flotation.  The Pro-Force dry spreader can handle common fertilizer, compost, poultry litter, and cover crop seed with operator-friendly innovations, top-of-the-line performance, and heavy-duty components for professional producers looking to maximize yield. With the optional Duo-, Tri- or Quad Force multi-hopper options, you can spread up to four different products at the same time, each with a variable rate. Pull-type model capacities range from 14 tons up to 26 tons and chassis-mounted hoppers are available from 8.5 tons up to 20 tons.  These features make the Pro-Force dry granular spreader the ideal match for commercial applicators, professional producers, and growers of all sizes.

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Large Carrying Capacities

Pull-type models include 2650, 2250, 1850, and 1450 with capacities of 26 tons, 22 tons, 18 tons, and 14 tons respectively.  Chassis-mounted hoppers are available in models 2050, 1850, 1650, 1450, 1350, 1250 and 1150 and feature capacities of 20 tons, 18 tons, 16 tons, 14 tons, 13 tons, and 8.5 tons respectively.

Premium Design

The hopper is 102” wide with 12" sideboards (except for the 1250 model) and is constructed of premium 304 stainless steel for the most corrosive-resistant, longest-lasting finish.

The 50° side slopes, which are among the steepest for a dry fertilizer spreader, ensure quick and complete cleanout and feature struck capacities ranging from 840 to 270 cubic feet.

Duo-, Tri- & Quad Force

Unverferth Duo-Force

Multi-Hopper Options

The Pro-Force dry fertilizer spreader can be equipped with multi-hopper options that allow you to spread 2, 3, or 4 separate products at the same time, each with a variable rate.   The Duo-, Tri-, and Quad Force options can be added or removed from the Pro-Force dry spreader main hopper at any time because the back panel of the main hopper does not need to be removed.

The optional 175 cubic-foot (120 cubic foot on 12' models) Duo-Force insert goes inside the main hopper and allows the operator to spread 2 separate products, at the same time, with independent variable rate control.   The Duo-Force insert utilizes a 34" wide mesh chain for conveying the dry material, providing consistent spread patterns with the main hopper's 34" wide belt-over-chain conveyor.

On 22' to 13' models, add the Tri-Force hopper attachment, which hangs on the back panel of the spreader, for a 75 cubic-foot micro-nutrient hopper for spreading 3 separate products.   The Tri-Force attachment utilizes a wide mesh chain for conveying the dry material.

For maximum versatility, add the Quad Force hopper insert divider, which goes inside of the Tri-Force hopper attachment, for spreading 4 separate products at the same time, each with variable rate control.   The Quad Force hopper insert utilizes a metering roller for conveying the dry material.

Unverferth Pro-Force Bin Level Sensor

Convenience Features

The hopper features a standard bin-level sensor that alerts the operator when the hopper is getting low on material.  The standard window in the front hopper panel allows the operator to easily see the contents inside.

An inverted Vee structure in the hopper protects the belt-over-chain and helps break up material when loading with an end loader.

Conveniently located control valves near the front of the hopper provide a clean working environment.

Spreading System

Pinpoint Accuracy

Spread common fertilizer up to 90’, lime and gypsum up to 60’, soybean and cover crop seed up to 70’, and compost up to 45’ with pinpoint accuracy because of the field-proven spinner design.

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Spinner Disks

Dual 30” spinner assemblies feature a ¾” deep dished design and 6 of the most aggressive fins in the industry that produce a wider spread pattern with precision application rates, even in windy conditions.  The ¾” dish design in each spinner disk optimizes the departure angle of the dry material for consistent spread patterns.

Each spinner disk is mounted to a jackshaft assembly, not pressed directly onto the hydraulic motor output shaft.  This design limits side stress on the hydraulic motor and reduces regular maintenance requirements.

The spinner disk platform assembly features multiple pre-defined settings for quick and easy fore-and-aft adjustment. This operator-friendly design ensures that the correct setting is selected every time it is operated, whether you're spreading fertilizer, lime, compost, or any other material. 


The 34” wide belt-over-chain conveyor system provides a leak-free seal for accurately dispensing material onto the spinner disks.  The vee-cleat rubber belt is fastened to the chain for worry-free operation.

A pintle chain is the backbone of the belt and provides more than 60,000 lbs. of high-tensile strength.  The chain tensioning system features an inspection area to easily monitor the chain for optimum life. 

The gearbox drive system for the belt-over-chain conveyor features the largest spur gear in the industry, heavy-duty gearcase and utilizes 4140 forged sprockets for longer life.
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End Gate

The fixed material divider at the end of the belt-over-chain conveyor ensures even distribution to each spinner.  The removable hillside baffle holds material in place when traveling through uneven terrain.  The end gate door features a convenient handle and measurement decal to ensure the door is opened to the correct height.

Pull-Type Spreaders


Pull-type models are available with an 840, 710, 580, or 450 cubic-foot capacity hopper, which are among the largest in the fertilizer spreader industry!  840 cubic foot model is for spreading compost or poultry litter only and all models feature standard 12” sideboards.


The Raven RCM ISOBUS rate controller is standard equipment and allows the operator to use the tractor’s virtual terminal screen to control the rate.  An on/off master foot switch is included in conjunction with the ISOBUS rate control system.


The fully adjustable axle can achieve row spacings from 76” to 120” with single wheels and tires and 60” through 152” with dual wheels and tires to accommodate row spacings ranging from 22” to 38”.

All models feature a side-mounted, ergonomic ladder that unfolds away from the hopper for easy climbing, transport lighting, and a safety chain for safer road travel.

Choose from high-flotation IF900/65x32 CFO single tires or if equipped with row crop duals, choose 480/80x46, VF380/90x46 or 320/105x54 tires depending on row spacing.

In-Line Walking Tandems

Models 2650, 2250 and 1850 are available with an optional in-line walking tandem undercarriage that allows for 15° of upward and 15° of downward movement for a total of 30° of travel in the field.


The optional 36” wide x 112” long hydraulically tensioned track system features a 106” rigid axle for the greatest in-field flotation.  The track system features a 2-bogie design, 32” main end wheels with 8-bolt hubs, cast-iron pivoting bogie wheels and convenient pressure gauge for verifying the belt tension.

Additional Features

Standard protective covers under the hopper prevent corrosive material from falling onto the pull-type undercarriage.  The pulling tractor requires 38 gallons per minute of hydraulic flow, 2 SCV remotes, and a case drain for proper operation.

Pull-Type Options

For accurate weight recording and in-field calibration, the optional scale system features an innovative design for accurate weight measurements.  Models 2650 to 1850 feature a 6-point shear-beam load cell design and the 1450 model features a 4-point shear-beam load cell design.   The scale system will work directly through the VT screen in your tractor cab, or you can opt for a separate 410 indicator to operate the scale system.

Additional pull-type model accessories include hydraulic disc brakes and 304 stainless steel fenders that protect the hopper from debris.  The fender option brings the overall width of the spreader to 132”.

Chassis-Mount Spreaders

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Chassis-mount spreaders are available with a 645, 580, 515, 450, 415 or 270 cubic-foot capacity hopper.  The 270 cubic-foot models is specifically designed for self-propelled sprayer chassis and can be equipped with optional 4” or 12” sideboards to increase the capacity to 300 or 385 cubic feet.

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When mounting to a floater chassis or a self-propelled sprayer, it is always important to note the maximum capacity of the chassis when mounting a spreader hopper.  Lift lugs are standard and permit easy handling when installing or removing the hopper.

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Chassis-Mount Options

Options for the chassis-mount spreaders include mud flaps to protect the front and rear of the unit, an oil cooler system, a hydraulic unloader valve for tractors without a PTO, a hydraulic gear pump for mounting to a chassis with an air system and ball valves for chassis that do not have hydraulic on/off.

Options & Accessories


The roll-tarp system with stainless steel end caps is available to protect the hopper’s contents.  Electric operation of the roll-tarp is also available and provides added operator convenience.

Other Options

Additional options for the Pro-Force dry fertilizer spreader include a 2nd heavy-duty gearbox on models 1350 and larger which places one gearbox on each side of the belt-over-chain conveyor for even distribution.  An optional #2 conveyor chain is available in lieu of the belt-over-chain for spreading compost and poultry litter.


Model 2650 2250 2050 1850 1650 1450 1350 1250 1150
Due to continuing improvements in the design and manufacture of Unverferth products, all specifications contained herein are subject to change without notice.
Hopper Length 26' 22' 20' 18' 16' 14' 13' 12' 11'
Hopper Width 8' 6" 7' 10"
Hopper Height 6' 10" 5' 10" 5' 3"
6' 10" (with 12" sides) 5' 11" (with 8" sides)
Hopper Side Slopes 50°
Hopper Material 10-Guage 304 Stainless Steel
Struck Capacity - Cubic Feet 840 (Litter & Compost Only) 710 645 580 515 450 415 270 200
300 (with 4" sides) 256 (with 8" sides)
385 (with 12" sides) 256 (with 8" sides)
Duo-Force Struck Capacity - Cubic Feet 175 (reduces the main hopper capacity by this amount) 120 80
138 (with 4" sides) 110 (with 8" sides)
175 (with 12" sides) 110 (with 8" sides)
Tri-Force Struck Capacity - Cubic Feet 75 - -
Quad Force Struck Capacity - Cubic Feet 37.5 (reduces the Tri-Force hopper capacity by this amount) - -
Capacity - Tons of Fertilizer Litter & Compost Only 22 20 18 16 14 13 8.5 6
9.5 (with 4" sides) 8 (with 8" sides)
12 (with 12" sides) 8 (with 8" sides)
Duo-Force Capacity - Tons of Fertilizer 6 (reduces the main hopper capacity by this amount) 3.75 2.5
4.5 (with 4" sides) 3.5 (with 8" sides)
6 (with 12" sides) 3.5 (with 8" sides)
Tri-Force Capacity - Tons of Fertilizer  - 3 - -
Quad Force Capacity - Tons of Fertilizer  - 1.5 (reduces the Tri-Force hopper capacity by this amount) - -
Pull-Type Overall Length 35' 3" 31' 3" - 27' 3" - 23' 3" - - -
Pull-Type Overall Height 10' 4" 10' 4" - 10' 4" - 10' 4" - - -
Pull-Type Transport Width 11' 3" 11' 3" - 11' 3" - 11' 3" - - -
Pull-Type Weight in lbs. - 13,600 - 12,600 - 10,800 - - -
Loaded Tongue Weight in lbs. - 8,900 - 7,000 - 5,900 - - -
Pull-Type Spinner Ground Clearance 40" 40" - 40" - 40" - - -