631K (Tier 4 Final/Stage IV)


180° Curb-to-Curb Turning Width40.12 ft (12.23 m)
Fuel Tank Refill Capacity - Scraper231 gal (US) (874 l)
Maximum Depth of Cut17.7 in (450 mm)
Maximum Depth of Spread21.1 in (535 mm)
631K Wheel Tractor-Scraper


180° Curb-to-Curb Turning Width40.12 ft (12.23 m)
Fuel Tank Refill Capacity - Scraper231 gal (US) (874 l)
Maximum Depth of Cut17.7 in (450 mm)
Maximum Depth of Spread21.1 in (535 mm)
Overall Shipping Height12.75 ft (3.89 m)
Overall Width12.93 ft (3.94 m)
Rated Load37 200 kg (82,200 lb); 37.2 tonnes (41.1 tons)
Scraper Capacity - Heaped34 yd³ (26 m³)
Scraper Capacity - Struck24 yd³ (18.3 m³)
Tires - Scraper37.25R35**E3
Tires - Tractor37.25R35**E3
Top Speed - Loaded34.7 mile/h (55.8 km/h)
Width - Cut11.5 ft (3.51 m)
EmissionsCat C18 ACERT engine meets U.S. EPA Tier 4 Final/EU Stage IV emission standards.
Engine Model - TractorCat C18 ACERT™
Flywheel Power - Tractor570 HP (425 kW)
Rated Engine RPM - Tractor1900 r/min (1900 r/min)
Flywheel Power - Tractor/Scraper570 HP (425 kW)
Scraper Capacity - Heaped34 yd³ (26 m³)
Top Speed - Loaded34.7 mile/h (55.8 km/h)
Cooling System19.8 gal (US) (75 l)
Crankcase - Tractor13.7 gal (US) (52 l)
Diesel Exhaust Fluid (DEF)8 gal (US) (30.5 l)
Fuel Tank231 gal (US) (874 l)
Hydraulic System37.5 gal (US) (142 l)
Transmission System29 gal (US) (110 l)
Front of Tractor to Front Axle142.2 in (3612 mm)
Axle to Vertical Hitch Pin20 in (509 mm)
Wheel Base346.8 in (8808 mm)
Rear Axle - Rear of Machine108 in (2744 mm)
Ground Clearance - Tractor26.1 in (664 mm)
Height - Overall Shipping153.2 in (3892 mm)
Height - Scraper Blade Maximum20 in (510 mm)
Height - Top of Cab147 in (3733 mm)
Length - Maximum (Push-Pull)655.1 in (16640 mm)
Length - Overall Machine - Standard597 in (15164 mm)
Width - Inside of Bowl134 in (3404 mm)
Width - Outside Rear Tires143.2 in (3636 mm)
Width - Overall Machine155 in (3937 mm)
Width - Rear Tire Centers96.9 in (2462 mm)
Width - Tractor137.8 in (3499 mm)
Operating Weight - Empty102750 lb (46600 kg)
Overall Length49.34 ft (15.04 m)
Operating Weight - Empty106430 lb (48275 kg)
Overall Length - With Bail Down54.59 ft (16.64 m)
Exterior Sound LevelThe exterior sound power level for the standard machine (ISO 6393) is 111.5 dB(A).
ROPS/FOPSROPS/FOPS meet “ISO Standards.”
BrakesISO 3450:2011
Falling Object Protective Structure (FOPS)ISO 3449:2005 Level II
Reverse AlarmISO 9533:2010
Rollover Protection Structure (ROPS)ISO 3471:2008 for up to 21 282 kg (46,919 lb)
Seat BeltSAE J386:FEB2006
Steering SystemISO 5010:2007
Transmission Gear - Eighth34.7 mile/h (55.8 km/h)
Transmission Gear - Fifth14.1 mile/h (22.7 km/h)
Transmission Gear - First3.4 mile/h (5.5 km/h)
Transmission Gear - Fourth10.5 mile/h (16.9 km/h)
Transmission Gear - Reverse6.2 mile/h (9.9 km/h)
Transmission Gear - Second6.2 mile/h (10 km/h)
Transmission Gear - Seventh25.7 mile/h (41.4 km/h)
Transmission Gear - Sixth19 mile/h (30.6 km/h)
Transmission Gear - Third7.7 mile/h (12.4 km/h)
Apron Lower3.8 s (3.8 s)
Apron Raise4 s (4 s)
Bail Lower2.1 s (2.1 s)
Bail Raise1.5 s (1.5 s)
Bowl Lower3.5 s (3.5 s)
Bowl Raise3.5 s (3.5 s)
Ejector Extend8.5 s (8.5 s)
Ejector Retract8.5 s (8.5 s)

Benefits and Features

The fuel, water and engine oil are relocated at ground level on the right hand side of the machine for easy access.

Have been changed from an air actuated drum shoe brake to a hydraulic actuated tractor wet disc brake and a scraper dry caliper.

This feature will allow the machine to control the slip of the tractor tires only.

In the event of an engine over speed situation, the compression brake or brakes will automatically engage with no operator input. The machine determines the over speed condition based on rate of acceleration and applies compression brakes automatically.

With similar technology as the Cat® Advanced Ride Management seat suspension, this software 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.

K Series steering system design requires significantly less steering effort. The reduced steering effort will allow for decreased operator fatigue and a more efficient operator resulting in possible higher rates of production late in the work cycle.

This standard feature allows the machine to prevent the operator from engaging the differential lock when damage could occur.

The K Series cab interior improves operator comfort and visibility. The overall interior is 21% larger than the G Series cab.

This feature is designed to take the place of top gear selection. If the machine top speed needs to be limited the operator can select the top speed through the display or the top speed can be set in ET. This will allow the machine to find the correct gear that works best for the engine and transmission. Allowing the engine and transmission to select the correct gear to pull the load in most cases resulting in a lower engine load factor and lower fuel burn verses using top gear selection that required the machine to run at engine speeds at or close to high idle.

Ground Speed Control sets the desired top speed by the operator if job site conditions or segment speed limits require a speed less than full run out. Machine Speed Limit is intended for use when top speed needs to be limited for longer durations and Ground Speed Control is intended for use when the top speed needs to be reduced for shorter segments or intermediate periods of time. The operator can set the desired top speed and the machine will find the correct gear that works best for the engine and transmission.

This option uses cylinder position sensors to automate bowl, apron and further implement controls throughout the four core work cycles: Dig, Haul, Unload and Return. When utilized this can reduce up to 14 individual operator commands per cycle. Sequence Assist simplifies control over the implements, reduces joystick usage, automatically controls cushion hitch, transmission hold and ejector.

The Payload Estimator will calculate the payload of the machine in tonnes or tons by measuring the bowl lift cylinder pressures at the beginning of the loaded haul segment. This feature works best when using Sequence Assist. Using Payload Estimator during testing has achieved better than 95% accuracy when compared to actual scale weights. The Payload Estimator feature comes automatically when a machine is ordered with Sequence Assist.

Is designed to help shorten the learning curve of inexperienced operators to ensure consistency and faster loading of material while reducing effort of the operator. Based on the speed of the machine, Load Assist automatically adjusts the cutting edge height to manage wheel slip and to ensure consistent and efficient loading in bulk earthmoving applications.

Intelligently ensures the machine does not cut below grade in the cut area or over fill in the fill area – avoiding rework and moving unnecessary material.

Standard Equipment

  • Cat C18 ACERT engine with MEUI™
  • Braking system:
    • Primary and secondary, dry caliper, hydraulic actuated
  • Alternator, 150 Amp
  • HVAC system, heat, AC, defrost
  • Extended Life Coolant to –37° C (–34° F)
  • Bowl:
    • 18.3 m3 (24 yd3), struck
    • 26 m3 (34 yd3), heaped

Optional Equipment

  • Secondary Steering Arrangement
  • Sequence Assist Arrangement with Payload Estimator
  • Camera arrangement – Work Area Vision System (WAVS)
  • Film arrangement – U.S. (ANSI)