The Caterpillar 120M is a motor grader designed for road construction, maintenance, and grading applications. It is part of Caterpillar's M Series lineup and is commonly used for shaping surfaces, maintaining gravel roads, ditching, and fine grading work. The 120M typically features a front-mounted blade, articulated frame, and operator controls suited for precise moldboard adjustment. It is used in municipal, construction, mining, and site preparation environments. The model is known for its balance of maneuverability, visibility, and grading control. Specifications may vary by configuration, year, and market, including engine output, operating weight, blade width, and drivetrain options.
Blades
Caterpillar 120M Motor Grader Blades specifications
Blade Tip Range - Backward
5 degrees
Blade Tip Range - Forward
40 degrees
Circle Centershift - Left
25.80 in (65.53 cm)
Circle Centershift - Right
25.80 in (65.53 cm)
Maximum Blade Position Angle
90 degrees
Maximum Depth of Cut
28.30 in (71.88 cm)
Maximum Lift Above Ground
16.80 in (42.67 cm)
Maximum Shoulder Reach Outside of Tires - Left
68.60 in (174.24 cm)
Maximum Shoulder Reach Outside of Tires - Right
75.00 in (190.50 cm)
Moldboard Sideshift - Left
20.10 in (51.05 cm)
Moldboard Sideshift - Right
26.00 in (66.04 cm)
Circle
Caterpillar 120M Motor Grader Circle specifications
Blade Tip Angle - Front
40 degrees
Blade Tip Angle - Rear
5 degrees
Diameter
60.20 in (152.91 cm)
Max Lift Above Ground
16.80 in (42.67 cm)
Max Reach Outside Tires - Left
68.60 in (174.24 cm)
Max Reach Outside Tires - Right
75.00 in (190.50 cm)
Shift Left
25.80 in (65.53 cm)
Shift Right
25.80 in (65.53 cm)
Dimensions
Caterpillar 120M Motor Grader Dimensions specifications
Blade Base
8.30 ft (2.53 m)
Front Ground Clearance
1.90 ft (0.58 m)
Ground Clearance - Rear Axle
13.60 in (34.54 cm)
Height - Exhaust Stack
112.40 in (285.50 cm)
Height - Front Axle Center
22.50 in (57.15 cm)
Height - Top of Cab
10.80 ft (3.29 m)
Height - Top of Cylinders
113.70 in (288.80 cm)
Height to Top of Isomount Cab
10.80 ft (3.29 m)
Length - Between Tandem Axles
59.50 in (151.13 cm)
Length - Counterweight to Ripper
389.30 in (988.82 cm)
Length - Front Axle to Mid Tandem
232.80 in (591.31 cm)
Length - Front Axle to Moldboard
98.90 in (251.21 cm)
Length - Front Tire to Rear of Machine
334.10 in (848.61 cm)
Overall Length
27.90 ft (8.50 m)
Rear Ground Clearance
1.20 ft (0.37 m)
Tandem Axle Wheelbase
5.00 ft (1.52 m)
Wheelbase
19.40 ft (5.91 m)
Width - Outside Front Tires
97.70 in (248.16 cm)
Width - Outside Rear Tires
97.70 in (248.16 cm)
Width - Tire Center Lines
84.10 in (213.61 cm)
Width Over Tires
8.20 ft (2.50 m)
Engine
Caterpillar 120M Motor Grader Engine specifications
Base Power (1st Gear) - Net
138.00 hp (102.91 kw)
Base Power (1st Gear) - Net - Metric
140.00 hp (104.40 kw)
Base Power (All Gears) - Net
138.00 hp (102.91 kw)
Bore
4.20 in (10.67 cm)
Derating Altitude
11,500.00 ft (3,505.20 m)
Displacement
403.00 cu in (6,604.00 cu cm)
Emissions
U.S. EPA Tier 3/EU Stage IIIA equivalent
Engine Model
Cat C6.6 ACERT
High - Ambient Capability
122 degrees
High Ambient - Fan Speed - Maximum
1650 rpm
High Ambient - Fan Speed - Minimum
600 rpm
Max Power
138.00 hp (102.91 kw)
Maximum Torque
690.00 lbs ft (935.50 nm)
Net Power Gears 7-8
138.00 hp (102.91 kw)
Number of Cylinders
6
Power Measured @
2000 rpm
Speed at Rated Power
2000 rpm
Standard - Ambient Capability
109 degrees
Standard - Fan Speed - Maximum
1150 rpm
Standard - Fan Speed - Minimum
600 rpm
Stroke
5.00 in (12.70 cm)
Torque Rise - V Plus
40%
V Plus Range - Net
103-136 kW (138-182)
V Plus Range - Net - Metric
103-136 kW (140-185)
V Range - Net
103-114 kW (138-153)
Frame
Caterpillar 120M Motor Grader Frame specifications
Circle - Blade Beam Thickness
1.40 in (3.56 cm)
Circle - Diameter
60.20 in (152.91 cm)
Drawbar - Height
6.00 in (15.24 cm)
Drawbar - Thickness
0.40 in (1.02 cm)
Drawbar - Width
3.00 in (7.62 cm)
Front Axle - Height to Center
22.50 in (57.15 cm)
Front Axle - Total Oscillation per Side
32 degrees
Front Axle - Wheel Lean - Left/Right
18 degrees
Front Frame Structure - Height
0.90 ft (0.27 m)
Front Frame Structure - Width
0.90 ft (0.27 m)
Front Axle
Caterpillar 120M Motor Grader Front Axle specifications
Ground Clearance
1.90 ft (0.58 m)
Oscillation - Total
32 degrees
Wheel Lean
18 degrees
Hydraulic System
Caterpillar 120M Motor Grader Hydraulic System specifications
Circuit Type
Electro-hydraulic load sensing closed center
Maximum System Pressure
3500 psi
Pump Flow
40.00 gpm (151.40 lpm)
Pump Output
40.00 gpm (151.40 lpm)
Pump Type
Variable piston
Relief Valve Pressure
3500 psi
Standby Pressure
450 psi
Moldboard
Caterpillar 120M Motor Grader Moldboard specifications
Arc Radius
16.30 in (41.40 cm)
Blade Down Pressure
28,887.20 lbs (13,103.03 kg)
Blade Down Pressure - Base GVW
16,435.00 lbs (7,454.80 kg)
Blade Down Pressure - Maximum GVW
29,125.00 lbs (13,210.89 kg)
Blade Pull - Base GVW
20,350.00 lbs (9,230.62 kg)
Blade Pull - Maximum GVW
24,218.00 lbs (10,985.11 kg)
Blade Pull at Max Weight
40,221.00 lbs (18,243.96 kg)
Blade Width
12.00 ft (3.66 m)
Cutting Edge Thickness
0.60 in (1.52 cm)
Cutting Edge Width
6.00 in (15.24 cm)
End Bit - Thickness
0.60 in (1.52 cm)
End Bit - Width
6.00 in (15.24 cm)
Max Depth of Cut
28.30 in (71.88 cm)
Moldboard - Height
24.00 in (60.96 cm)
Moldboard - Thickness
0.90 in (2.29 cm)
Moldboard - Width
12.00 ft (3.66 m)
Moldboard Height
24.00 in (60.96 cm)
Moldboard Length
12.00 ft (3.66 m)
Moldboard Thickness
0.90 in (2.29 cm)
Moldboard Width
12.00 ft (3.66 m)
Side Shift Left
20.10 in (51.05 cm)
Side Shift Right
26.00 in (66.04 cm)
Throat Clearance
5.20 in (13.21 cm)
Operating Specifications
Caterpillar 120M Motor Grader Operating Specifications specifications
Articulation Angle - Left/Right
20 degrees
Circle Gearbox Fluid Capacity
1.80 gal (6.81 l)
Cooling System Fluid Capacity
10.40 gal (39.36 l)
Forward - 1st
2.40 mph (3.86 kph)
Forward - 2nd
3.30 mph (5.31 kph)
Forward - 3rd
4.80 mph (7.72 kph)
Forward - 4th
6.50 mph (10.46 kph)
Forward - 5th
10.20 mph (16.42 kph)
Forward - 6th
13.80 mph (22.21 kph)
Forward - 7th
19.00 mph (30.58 kph)
Forward - 8th
27.70 mph (44.58 kph)
Fuel Capacity
90.00 gal (340.65 l)
Hydraulic System Fluid Capacity
15.90 gal (60.18 l)
Max Operation Weight - Front Axle
16,312.00 lbs (7,399.01 kg)
Max Operation Weight - Rear Axle
28,378.00 lbs (12,872.06 kg)
Max Operation Weight - Total
44,690.00 lbs (20,271.07 kg)
Operating Weight
31,069.00 lbs (14,092.68 kg)
Rear Diff/Final Drive Fluid Capacity
13.20 gal (49.96 l)
Reverse - 1st
2
Reverse - 2nd
3.80 mph (6.12 kph)
Reverse - 3rd
5.60 mph (9.01 kph)
Reverse - 4th
8.60 mph (13.84 kph)
Reverse - 5th
16.10 mph (25.91 kph)
Reverse - 6th
23.50 mph (37.82 kph)
Std Operation Weight - Front Axle
8,233.00 lbs (3,734.43 kg)
Std Operation Weight - Rear Axle
22,836.00 lbs (10,358.25 kg)
Std Operation Weight - Total
31,069.00 lbs (14,092.68 kg)
Steering Range - Left/Right
47.5 degrees
Tandem Case Fluid Capacity (each)
16.90 gal (63.97 l)
Top Speed - Forward
27.70 mph (44.58 kph)
Top Speed - Reverse
23.50 mph (37.82 kph)
Turning Radius - Outside Front Tires
24.50 ft (7.47 m)
Power Train
Caterpillar 120M Motor Grader Power Train specifications
Brakes - Parking
Multiple oil disc
Brakes - Secondary
Dual circuit control system
Brakes - Service
Multiple oil-disc
Brakes - Service - Surface Area
3,565.00 cu in (58,420.01 cu cm)
Forward/Reverse Gears
8 Fwd / 6 Rev
Transmission
Direct drive power shift countershaft
Ripper
Caterpillar 120M Motor Grader Ripper specifications
Machine Length Increase, Beam Raised
39.20 in (99.57 cm)
Penetration Force
17,705.00 lbs (8,030.86 kg)
Pry-Out Force
26,303.00 lbs (11,930.85 kg)
Ripper Shank Holder Spacing
21.00 in (53.34 cm)
Ripper Shank Holders
5
Ripping Depth - Maximum
17.00 in (43.18 cm)
Scarifier
Caterpillar 120M Motor Grader Scarifier specifications
