What is "grader"

Grader \Grad"er\, n.

1. One who grades, or that by means of which grading is done or facilitated.

2. Specifically: A vehicle used for levelling earth, esp. one with a plow blade suspended from the center, used specifically for grading roads.

1868, of machines; 1870, of persons, agent noun from grade (v.).

n. 1 A machine used in construction for flattening large surfaces 2 One who grades, or that by means of which grading is done or facilitated. 3 (context in combination English) One who belongs to a certain grade at school.

n. a judge who assigns grades to something

A grader, also commonly referred to as a road grader, a blade, a maintainer, or a motor grader, is a construction machine with a long blade used to create a flat surface during the grading process. Typical models have three axles, with the engine and cab situated above the rear axles at one end of the vehicle and a third axle at the front end of the vehicle, with the blade in between. In certain countries, for example in Finland, almost every grader is equipped with a second blade that is placed in front of the front axle. Some construction personnel refer to the entire machine as "the blade". Capacities range from a blade width of 2.50 to 7.30 m and engines from 93–373 kW (125–500 hp). Certain graders can operate multiple attachments, or be used for separate tasks like underground mining.

In civil engineering, the grader's purpose is to "finish grade" (to refine or set precisely). The "rough grading" is performed by heavy equipment or engineering vehicles such as scrapers and bulldozers.

Graders are commonly used in the construction and maintenance of dirt roads and gravel roads. In the construction of paved roads they are used to prepare the base course to create a wide flat surface upon which to place the asphalt. Graders are also used to set native soil foundation pads to finish grade prior to the construction of large buildings. Graders can produce inclined surfaces, to give cant (camber) to roads. In some countries they are used to produce drainage ditches with shallow V-shaped cross-sections on either side of highways.

A more recent innovation is the outfitting of graders with grade control technologies, such as those manufactured by Topcon Positioning Systems, Inc., Trimble Navigation, Leica Geosystems or Mikrofyn for precise grade control and (potentially) "stakeless" construction. Manufacturers such as Caterpillar have also begun integrating these technologies, like Cat Grade Control, into their machines so they're equipped out of the factory.