Bush-Whacker ST-121 10 Foot Smooth Top Brush Cutter


SpecificationsThe DifferenceComparison Chart
Gearboxes – 540 OR 1,000 RPM
, 250 HP main or transfer box with 1 ¾” 20 splined input and output shafts. Two spindle gearboxes, 250 HP, base mounted, 1:1.6 ratio. 20 splined 1 3/4” input shaft, 2 3/8” output shaft on spindle boxes. All gearboxes have forged alloy steel malleable housings, carburized and hardened gears and shafts, tapered and ball bearing.

Drive Shafts – Shielded PTO’s made from the finest quality propeller shaft material and needle bearing universal joints. Category 4 main input and side drives. Category 4 jack shaft for pull model. Category 4 80-degree constant velocity main drive shaft optional for pull model.

Slip Clutch – Heavy-duty clutch with spring type adjustment and four friction discs on main shaft, outboard protection by means of shock absorbing rubber elements connected to splined yokes which form a coupler.

Blades – 1/2” x 4” material, alloy spring steel, airlift design, free-swinging when encountering obstructions, 6 inch overlap for better cutting. Blade tip speed: 15,800 fpm.

Wheels – Two solid rubber tires standard. Independent shock absorbing system for all wheel axles. Optional: aircraft tires or implement tires, dual axle arms (4 tires total).

Bush-Whacker Special Deck – Bush-Whacker Special Deck includes a primary (bottom) deck of 7 gauge steel that is welded to heavy duty heavy tubing structures. The smooth, easy-to-clean top deck is made of 12 gauge steel and protects the inner support frame. Combined deck thickness: .2921”.

Hydraulic Adjustments – Hydraulic cylinder controls cutting and traveling height adjustments for pull and semi mount models (optional for lift model).

Dimensions – Cutting width: 121 inches. Cutting height: adjustable from 2” to 15”. Axles adjustable from 24” centers to 40” centers for row crops. Overall width: 131”. Overall length: 140”. Transportation wide: 131”. Cutting height for aircraft and implement tires: 2” to 17”.

Weight -3,565 lbs.

Chain Guards Front & Rear

Other Standard Features – Replaceable skid shoes. For pull model: heavy-duty tongue assembly with dual leveling rods, hydraulic hose holder, jack for easy hookup and unhooking from tractor.

Specifications listed are standard; however, any State Department of Transportation specifications that may differ from standard Bush-Whacker® specifications will take precedence and be implemented into production.

  • 7 Gauge Deck.
  • Structural frame of mower is 3” by 4” tubing with 7 gauge wall thickness.
  • Gearboxes are mounted to 3/8” plates that are welded to the 7 gauge deck.
  • 8-bolt mounting on gearboxes – heads are tack-welded to bottom of deck so one person can tighten the nuts or change the gearbox.
  • Blades are 1/2” by 4” instead of traditional 1/2” by 3 1/2”.

Comparison 10′ Brush Cutters

BrandBush-WhackerBush HogJohn DeereSchulteRhino
ModelST-121 (540 or 1,000 RPM)3210HX10FX210SE10A
Cutting Heights2”-17”2”-13”1”-12”2”-14”1 1/4” – 12”
Cutting Capacity4”2.5”3”3”1”
Deck Thickness7 Gauge / 12 Gauge10 Gauge10 Gauge10 Gauge10 Gauge
Side Skirt Thickness1/4″1/4″10 Gauge1/4″1/4″
Divider Gearbox HP250 HP205 HP180 HP205 HP100 HP
Spindle Gearbox HP250 HP190 HP140 HP190 HP70 HP
Blade Size1/2” x 4” with 3/4”1/2” x 4”1/2” x 4”1/2” x 4”.401” x 3”
Blade Tip Speed14,600 FPM / 27,032 FPM16,881 FPM16,889 FPM16,100 FPM15,771 FPM
Blade Overlap6”3”2.8”5”4”
Weight3,565 lbs.2,741 lbs.2,326 lbs.2,915 lbs.1,759 lbs.
Safety DeflectorsChain GuardsRubber BeltingChain GuardsDouble Chain GuardsDouble Chain Guards
Mower Warranty1 Year Limited1 Year Limited1 Year Limited1 Year Limited1 Year Limited
Gearbox Warranty5 Year Limited5 Year Limited5 Year Limited5 Year Limited5 Year Limited

Hall Manufacturing provides a limited warranty of one year on any machine or component, and five years on any mechanical gearbox or gearbox component.

This warranty covers defective materials and workmanship on the complete machine. Limitations and exclusions apply.