Great deals on selected construction Cat® equipment available now! T&Cs apply. View Promotion

Gear up and get to work with limited-time deals on select Cat® construction equipment. While stock lasts. View Promotion

Please use a desktop browser to compare products.
Metric | Imperial
621
Open Bowl Scrapers
621
Change product
657
Open Bowl Scrapers
657
Change product
631 - Tier 2
Open Bowl Scrapers
631 - Tier 2
Change product
General Expand Collapse
Overall Width
11.8 ft 3.57 m
12.93 ft 3.94 m
Overall Shipping Height
13.22 ft 4.03 m
12.75 ft 3.89 m
Scraper Capacity - Struck
17.1 yd³ 13.0 m³
24 yd³ 18.3 m³
Scraper Capacity - Heaped
24.0 yd³ 18.4 m³
44 yd³ 33.6 m³
34 yd³ 26 m³
Rated Load
26 127 kg (57,600 lb); 26.19 tonnes (28.81 tons)
104,058 lb 47,200 kg
37 200 kg (82,200 lb); 37.2 tonnes (41.1 tons)
Width - Cut
10.4 ft 3.14 m
11.50 ft 3.51 m
Maximum Depth of Cut
12.4 in 315.0 mm
17.7 in 450 mm
Maximum Depth of Spread
21.3 in 540.0 mm
21.1 in 535 mm
Top Speed - Loaded
33.5 mile/h 53.9 km/h
33 mile/h 56.1 km/h
34.7 mile/h 55.8 km/h
180° Curb-to-Curb Turning Width
38.71 ft 11.8 m
40.12 ft 12.23 m
Tires - Scraper
33.25R29**E3
37.25R35**E3
Tires - Tractor Drive
33.25R29**E3
Fuel Tank Refill Capacity - Scraper
201.0 gal (US) 763.0 l
231 gal (US) 874 l
Rated Engine RPM - Tractor
2000.0 r/min 2000.0 r/min
1900 r/min 1900 r/min
Engine Model - Tractor
Cat® C13
Cat® C18
Flywheel Power - Tractor
407.0 hp 304.0 kW
570 hp 425 kW
Note
Meets U.S. EPA Tier 4 Final/EU Stage V emission standards, or noncertified and equivalent to U.S. EPA Tier 2, or noncertified and equivalent to U.S. EPA Tier 3/EU Stage IIIA.
Flywheel Power - Tractor/Scraper
304 kW (407 hp)
469kW (629 hp) / 353 kW (473 hp)
570 hp 425 kW
Operating Weight - Empty
79774.0 lb 36385.0 kg
102750 lb 46600 kg
Overall Length
45.10 ft 14.02 m
49.34 ft 15.04 m
Operating Weight - Empty
79774.0 lb 36385.0 kg
102750 lb 46600 kg
Overall Length - With Bail Down
51.1 ft 15.58 m
54.59 ft 16.64 m
Scraper Capacity - Heaped
24.0 yd³ 18.4 m³
44 yd³ 33.6 m³
34 yd³ 26 m³
1 Forward
3.1 mile/h 5.0 km/h
3.5 mile/h 5.7 km/h
2 Forward
5.5 mile/h 8.9 km/h
6.5 mile/h 10.5 km/h
3 Forward
7.5 mile/h 12.1 km/h
7.8 mile/h 12.5 km/h
4 Forward
10.1 mile/h 16.3 km/h
10.6 mile/h 17 km/h
5 Forward
13.6 mile/h 21.9 km/h
14.2 mile/h 22.8 km/h
6 Forward
18.4 mile/h 29.6 km/h
19.2 mile/h 30.9 km/h
7 Forward
24.8 mile/h 39.9 km/h
25.7 mile/h 41.4 km/h
8 Forward
33.5 mile/h 53.9 km/h
34.9 mile/h 56.1 km/h
Reverse
5.7 mile/h 9.2 km/h
6.7 mile/h 10.8 km/h
Top Speed - Loaded
33.5 mile/h 53.9 km/h
33 mile/h 56.1 km/h
34.7 mile/h 55.8 km/h
Final Drive - Each
5.0 Gal 19.0 l
6 gal (US) 29.5 l
8.71 gal (US) 33.0 l
Windshield Washer
1.3 Gal 5.0 l
0.5 gal (US) 5 l
Cooling System - Scraper
8.7 Gal 33.0 l
Crankcase
9.7 gal (US) 37.0 l
13.7 gal (US) 38 l
Transmission System
25.5 gal (US) 97.0 l
29 gal (US) 110 l
Cooling System
11.0 gal (US) 42.0 l
23.4 gal (US) 88.6 l
18.75 gal (US) 71 l
Diesel Exhaust Fluid (DEF)
8.1 Gal 30.5 l
8 gal(US)/d 30.5 l
Fuel Tank
216.01 gal (US) 818.0 l
430 gal (US) 1628 l
231 gal (US) 874 l
Hydraulic System
21.926 gal (US) 83.0 l
37.5 gal (US) 142 l
Width - Overall Machine
141.1 in 3585.0 mm
14.3 ft 4.36 m
155 in 3937 mm
Width - Tractor
133.1 in 3381.0 mm
12.3 ft 3.75 m
144.2 in 3662 mm
Width - Inside of Bowl
120.0 in 3048.0 mm
12.07 ft 3.68 m
134 in 3404 mm
Width - Outside Rear Tires
128.9 in 3275.0 mm
143.2 in 3636 mm
Height - Overall Shipping
158.6 in 4029.0 mm
15.29 ft 4.66 m
153.2 in 3892 mm
Height - Top of Cab
142.2 in 3612.0 mm
12.86 ft 3.92 m
149.8 in 3805 mm
Ground Clearance - Tractor
21.9 in 557.0 mm
2.3 ft 0.7 m
26.1 in 664 mm
Front of Tractor to Front Axle
122.8 in 3119.0 mm
14.93 ft 4.55 m
142.0 in 3608 mm
Axle to Vertical Hitch Pin
21.3 in 540.0 mm
1.8 ft 0.55 m
20 in 509 mm
Height - Scraper Blade Maximum
21.3 in 540.0 mm
2.17 ft 0.66 m
20 in 510 mm
Wheel Base
314.9 in 7998.0 mm
32.68 ft 9.96 m
346.8 in 8808 mm
Rear Axle - Rear of Machine
114.1 in 2898.0 mm
8.07 ft 2.46 m
108 in 2744 mm
Length - Maximum (Push-Pull)
613.2 in 15576.0 mm
655.1 in 16640 mm
Width - Overall Machine - Ladder Down
149.2 in 3790.0 mm
159.3 in 4045 mm
Length - Overall Machine - Standard
551.8 in 14015.0 mm
597 in 15164 mm
Width - Rear Tire Centers
90.2 in 2290.0 mm
96.9 in 2462 mm
ROPS/FOPS
Meets ISO standards
ROPS/FOPS meet “ISO Standards.”
Exterior Sound Level
The exterior sound power level for the standard machine (ISO 6395:2008) is 114 dB(A).
The exterior sound power level for the standard machine (ISO 6393) is 116 dB(A).
Reverse Alarm
ISO 9533:2010
ISO 9533:2010
Falling Object Protective Structure (FOPS)
ISO 3449:2005 Level II
ISO 3449:2005 Level II
Steering System
ISO 5010:2007
ISO 5010:2007
Rollover Protection Structure (ROPS)
ISO 3471:2008 for up to 17 084 kg (37,664 lb)
ISO 3471:2008 for up to 21 282 kg (46,919 lb)
Seat Belt
SAE J386:JUN1985
SAE J386:FEB2006
Brakes
ISO 3450:2011
Brakes ISO 3450:2011
Transmission Gear - Reverse
5.7 mile/h 9.2 km/h
6.2 mile/h 9.9 km/h
Transmission Gear - Third
7.5 mile/h 12.1 km/h
7.7 mile/h 12.4 km/h
Transmission Gear - First
3.1 mile/h 5.0 km/h
3.4 mile/h 5.5 km/h
Transmission Gear - Seventh
24.8 mile/h 39.9 km/h
25.7 mile/h 41.4 km/h
Transmission Gear - Fourth
10.1 mile/h 16.3 km/h
10.5 mile/h 16.9 km/h
Transmission Gear - Sixth
18.4 mile/h 29.6 km/h
19.0 mile/h 30.6 km/h
Transmission Gear - Fifth
13.6 mile/h 21.9 km/h
14.1 mile/h 22.7 km/h
Transmission Gear - Second
5.5 mile/h 8.9 km/h
6.2 mile/h 10.0 km/h
Transmission Gear - Eighth
33.5 mile/h 53.9 km/h
34.7 mile/h 55.8 km/h
Bail Lower
3.2 s 3.2 s
2.1 s 2.1 s
Apron Lower
3.8 s 3.8 s
3.8 s 3.8 s
Bowl Lower
3.5 s 3.5 s
3.5 s 3.5 s
Bail Raise
1.8 s 1.8 s
1.5 s 1.5 s
Ejector Retract
6.7 s 6.7 s
8.5 s 8.5 s
Ejector Extend
5.2 s 5.2 s
8.5 s 8.5 s
Apron Raise
3.0 s 3.0 s
4.0 s 4.0 s
Bowl Raise
3.3 s 3.3 s
3.5 s 3.5 s