The Cat 621 Wheel Tractor-Scraper

Wheel Tractor-Scraper K Series Wheel Tractor-Scraper K Series
Wheel Tractor-Scraper K-Series Operator Testimonial Wheel Tractor-Scraper K-Series Operator Testimonial
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Flywheel Power - Tractor/Scraper304 kW (407 hp)
Scraper Capacity - Heaped24 yd³ (18.4 m³)
Top Speed - Loaded33.5 mile/h (53.9 km/h)
Width - Overall Machine141.1 in (3585 mm)
Our wheel tractor-scrapers have long been considered the basic method of moving volumes of material, and the Cat® 621 Wheel Tractor-Scraper is no exception. Known for its ability to be push-loaded and high travel speeds, it’s always an earthmover’s first tool of choice when working in challenging load areas. With an open bowl and a single engine, this machine is designed to handle a wide range of material types ranging from sand to ripped rock 609.6 mm (24 ") or less in size.


Flywheel Power - Tractor/Scraper304 kW (407 hp)
Scraper Capacity - Heaped24 yd³ (18.4 m³)
Top Speed - Loaded33.5 mile/h (53.9 km/h)
Width - Overall Machine141.1 in (3585 mm)
Width - Tractor133.1 in (3381 mm)
Width - Inside of Bowl120 in (3048 mm)
Width - Outside Rear Tires128.9 in (3275 mm)
Height - Overall Shipping158.6 in (4029 mm)
Height - Top of Cab142.2 in (3612 mm)
Ground Clearance - Tractor21.9 in (557 mm)
Front of Tractor to Front Axle122.8 in (3119 mm)
Axle to Vertical Hitch Pin21.3 in (540 mm)
Height - Scraper Blade Maximum20.5 in (520 mm)
Wheel Base314.9 in (7998 mm)
Rear Axle - Rear of Machine114.1 in (2898 mm)
Falling Object Protective Structure (FOPS)ISO 3449:2005 Level II
Rollover Protection Structure (ROPS)ISO 3471:2008 for up to 17 084 kg (37,664 lb)
ROPS/FOPSMeets SAE and ISO standards
Exterior Sound LevelThe exterior sound power level for the standard machine (ISO 6393:2008) is 118 dB(A).
Operating Weight - Empty80630 lb (36567 kg)
BrakesISO 3450:1996
Reverse AlarmISO 9533:2010
Steering SystemISO 5010:2007
Seat BeltSAE J386:JUN1985
Transmission Gear - Reverse5.7 mile/h (9.2 km/h)
Bail Lower3.2 s (3.2 s)
Ejector Extend5.2 s (5.2 s)
Apron Lower3.8 s (3.8 s)
Bowl Lower3.5 s (3.5 s)
Ejector Retract6.7 s (6.7 s)
Bowl Raise3 s (3 s)
Apron Raise2.95 s (2.95 s)
Transmission Gear - Eighth33.5 mile/h (53.9 km/h)
Overall Length45.9 ft (14.02 m)
Transmission Gear - Fourth10.1 mile/h (16.3 km/h)
Transmission Gear - Third7.5 mile/h (12.1 km/h)
Transmission Gear - Second5.5 mile/h (8.9 km/h)
Transmission Gear - Sixth18.4 mile/h (29.6 km/h)
Transmission Gear - First3.1 mile/h (5 km/h)
Transmission Gear - Fifth13.6 mile/h (21.9 km/h)
Transmission Gear - Seventh24.8 mile/h (39.9 km/h)
Overall Length - With Bail Down51.1 ft (15.58 m)
Overall Shipping Height13.22 ft (4.03 m)
Operating Weight - Empty79787 lb (36185 kg)
Engine Model - TractorCat C13
Scraper Capacity - Heaped24 yd³ (18.4 m³)
Fuel Tank Refill Capacity - Scraper216.1 gal (US) (818 l)
Tires - Scraper33.25R29**E3
Width - Cut10.3 ft (3.14 m)
Maximum Depth of Spread21.3 in (540 mm)
Top Speed - Loaded33.5 mile/h (53.9 km/h)
Rated Load26 127 kg (57,610 lb); 26.19 tonnes (28.81 tons)
180° Curb-to-Curb Turning Width38.71 ft (11.8 m)
Scraper Capacity - Struck17.1 yd³ (13 m³)
Maximum Depth of Cut12.4 in (315 mm)
Tires - Tractor Drive33.25R29**E3
Flywheel Power - Tractor407 HP (304 kW)
Width - Rear Tire Centers90.2 in (2290 mm)
NoteCat C13 engine meets U.S. Environmental Protection Agency (EPA) Tier 4 Final/EU Stage IV engine emission standards.
Rated Engine RPM - Tractor2000 r/min (2000 r/min)
Hydraulic System21.926 gal (US) (83 l)
Crankcase8.08 gal (US) (30.58 l)
Transmission System24.76 gal (US) (93 l)
Cooling System11.89 gal (US) (45 l)
Fuel Tank216.09 gal (US) (818 l)
Diesel Exhaust Fluid8.057 gal (US) (30.5 l)
Overall Width11.75 ft (3.58 m)
Length - Overall Machine - Standard551.8 in (14015 mm)
Length - Maximum (Push-Pull)613.2 in (15576 mm)
Width - Overall Machine - Ladder Down149.2 in (3790 mm)
Bail Raise1.8 s (1.8 s)

Benefits and Features


  • Up to 8% improvement in productivity.
  • Advanced Productivity Electronic Control System (APECS) allows
    the engine and transmission to communicate on a high level. This communication allows the machine to better utilize the power
    and torque the engine is producing. The net result is moving more
  • Use Ground Speed Control to set the desired top speed and the
    machine will find the gear that works best for the engine and the
    transmission, providing a lower fuel burn.
  • The Machine Speed Limit feature replaces Top Gear Selection.
  • Auto-Stall assists in quickly bringing the transmission to an
    operating temperature at start-up when the machine is working in a
    cold climate region.
  • Boost productivity with the Payload Estimator feature (optional
    attachment). Payload Estimator is an automatic feature when
    ordered with Sequence Assist.
  • Cat®Payload Estimator for scrapers is an earthmoving solution for
    optimal payload and jobsite efficiency. Payload Estimator achieves on-the-go weighing by using bowl lift cylinder pressure during the
    loaded haul segment. Payload Estimator is optimized to be used
    with Sequence Assist, which provides increased productivity with
    less operator effort.


  • Reduce up to 14 individual operator commands per cycle with Sequence Assist (optional attachment).
  • Steer with less effort using the newly designed high-pressure 
    steering system.
  • Enjoy interior improvements and a more ergonomic work environment
     with a 21% larger cab than the G Series cab.
  • Intuitive, ergonomic controls keep operators focused on their work.
  • Maintain desired cab temperature with automatic temperature 


  • Get in and out of the cab easier with the new powered access
    ladder system (optional attachment).
  • Enhance an operator’s awareness of site surroundings with the
    optional Work Area Vision System (WAVS).
  • Seat belt indicator provides visual and audible alerts when the seat
    belt is not in use.
  • Advanced Cushion Hitch allows the cushion hitch to prevent end
    stroke by having the ability to predict end stroke events and manage
    the rate of dampening, resulting in reduced hitch maintenance and
    improved operator ride in rough conditions.


  • The spacious cab features easy, intuitive controls and excellent
    visibility. The cab provides a comfortable working environment for
    all-day operation.
  • Cat Advanced Ride Management (ARM) seat suspension reduces
    end stroke movement of the load cylinder for a smoother ride.
  • Engine overspeed protection will automatically engage with no
    operator input when the machine is in eighth gear. The machine
    will assist in slowing the machine speed by canceling the throttle
    command and engaging the engine compression brake.


  • Monitor, manage, and enhance jobsite operations.
  • Hit target grade faster and more accurately with Cat GRADE technologies. Finish jobs in fewer passes and with less operator effort, saving you time and helping to increase profit.
  • Product Link™ collects machine data that can be viewed online through web and mobile applications (optional attachment).
  • Access information anytime, anywhere with Vision Link®– use it to make informed decisions that boost productivity, lower costs, simplify maintenance, and improve safety and security on your jobsite.
  • Shorten the learning curve for inexperienced operators with Load Assist (optional attachment).


  • The new tractor hydraulic on-demand fan helps assist in lower fuel consumption.
  • The Cat C13 tractor engine meets U.S. EPA Tier 4 Final or EU Stage V emission standards, contributing to lower fuel consumption.
  • Using draft-arm overflow guards diverts material away from the bowl, preventing material from getting caught between the draft arms and the bowl sides.
  • Cat Grade Control (optional attachment) intelligently ensures the machine does not cut below grade in a cut area or overfill in the fill area.

Standard Equipment

  • Standard and optional equipment may vary. Consult your Cat dealer for details.
  • Cat C13 engine with MEUI™
  • Cat engine brake
  • Electric start, 24 Volt
  • Air cleaner, dry type with precleaner
  • Fan, hydraulic
  • Ground level engine shutdown
  • Radiator, aluminum unit core, 9 fins per inch
  • Guard, crankcase
  • Muffler (only for less or non-regulated regions engine arrangement only)
  • Starting aid, ether
  • Braking system: - Primary and secondary, wet disc, hydraulic - Parking, hydraulic-released, spring-applied - Throttle lock
  • Transmission: - 8-speed planetary power shift - ECPC control - APECS software - Programmable top gear selection - Transmission hold - Differential lock - Guard, power train - Standard tire spin reduction - Ground speed control - Machine speed limit - Differential lock protection
  • Braking system: - Primary and secondary, wet disc, hydraulic
  • Alternator, 150 Amp
  • Batteries (4), 12V, 1,000 CCA, maintenance free, high output
  • Electrical system, 24V
  • Lighting system: - Headlights, halogen - Turn signals with hazard function, LED floodlights, (2) cutting edge (1) bowl, halogen side vision (2)
  • Starting/charging receptacle
  • Alarm, backup
  • Lighting system: - Brake lights, LED - Turn signals with hazard function, LED
  • HVAC system, heat, AC, defrost
  • Thermostat control of HVAC system
  • Coat hook
  • Lunchbox platform with holding strap
  • Diagnostic connection (2)
  • 12V power ports (2)
  • Differential lock (1)
  • Dome courtesy light
  • Horn, electric
  • T-Handle implement control
  • Mirror, rearview
  • Radio ready
  • ROPS/FOPS cab, pressurized
  • Keypad switches: - Throttle lock - Wipers/washers - Hazard lights - Retarding level select - Work lights on, off - Information mode on Messenger Display
  • Safety tab rocker switches
  • Seat belt, static two-piece
  • Seat, Cat Advanced Ride Management (ARM), Cat Comfort Series 3, rotates 30 degrees
  • Steering wheel, tilt, telescoping, padded
  • Windows, right side emergency egress
  • Windows, sliding
  • Windows, laminated, zipped in
  • Windshield wipers, front and rear windows, includes washers
  • Door lock
  • Messenger Display
  • Gauges, warnings include: - Coolant temperature - Engine oil temperature - Hydraulic oil temperature - DPF temperature - Fuel level - Park brake - Implement lockout - Brake system - Regeneration required - Throttle lock - System voltage - Secondary steering - Bail down - Ejector auto - Differential lock - Apron float - Transmission hold - Cushion hitch - High beam lights - Action lamp - Engine speed, rpm - Gear selection - DEF fill levels
  • Extended Life Coolant to -37° C (-34° F)
  • Advanced cushion hitch
  • Accumulators (cushion hitch) with Canadian Registration Number (CRN)
  • Fast oil change
  • Fenders, non-metallic
  • Heater, engine coolant 120V
  • Rims (2)
  • Tow pin, front
  • Vandalism locks
  • Heater, engine coolant 120V
  • Bowl: - 18.4 m3 (24 yd3), heaped - 14.1 m3 (18.4 yd3), struck
  • Vandalism locks
  • Hydraulic position sensing cylinders (bowl lift and apron)

Optional Equipment

  • Standard and optional equipment may vary. Consult your Cat dealer for details.
  • Secondary Steering Arrangement
  • Sequence Assist Arrangement
  • Load Assist
  • Cat Grade Control with Load Assist
  • Cooling, high ambient HRC
  • Cooling, low ambient HRC
  • Cooling, high ambient LRC
  • Cooling, low ambient LRC
  • Camera arrangement - WAVS
  • Steering lock - external
  • Cab beacon
  • Air horn
  • Air horn and beacon
  • Fender, scraper
  • Guard, overflow
  • Wiring group
  • Year of manufacture plate
  • Film arrangement - U.S. (ANSI)
  • Film arrangement - International (ISO)