What is a Snow Plow Attack Angle?

January 19, 2018

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Few plow settings matter as much as the attack angle. It decides how well you clear, how long your cutting edges last and how hard the plow is on pavement. This guide explains the attack angle, recommends which angle to run, and shows how to check it before the season.

What is an attack angle?

A snow plow’s attack angle is the angle at which the blade meets the road. It matters on the large highway plows that state, county and city fleets run, because their angle can be adjusted. Contractor plows are built at a fixed angle, so this guide is for fleet plows.

The right angle clears snow and ice better. It also lets the cutting edge, guards and shoes meet the road the way they were designed to. They wear evenly and last longer, which keeps your plow running for years.

Choosing the right angle

The recommended range is 55° to 75°, based on University of Iowa tests cited by SIMA.

55°Best forPlowing unpaved gravel, and scooping up heavy snow
Recommended65°Best forThe best all-around angle for most surfaces and conditions
75°Best forPlowing paved surfaces and asphalt, and scraping hard-packed snow or ice

For most fleets, 65° is the place to start. Research has found that 65° clears aggressively while using the least fuel.

For scraping ice, a steeper 75° angle works best, according to University of Iowa tests.

Match the angle to your cutting edge

Many cutting edges are built to run at 65°. A standard tungsten carbide insert edge uses a trapezoid-shaped insert with a 25° angle. A 65° attack angle matches that insert angle, so the carbide meets the road as designed. Past 65°, the trapezoid shape starts to limit how well the edge works. Bullnose carbide insert edges are different, because their rounded insert works well across a wide range of angles.

Plow shoes and cutting edges with wear bars also set their own angle against the pavement. Most of them perform best at 65° too.

Some edges are made for other angles, and rubber edges, for example, can run as high as 90°. Always check the maker’s guidance for the edge you run.

How the wrong angle damages roads

A wrong attack angle can gouge the road and peel the surface away. It can also rip up chip seal, center lines, paint and reflectors, and scratch decorative pavement. Even a few degrees off can cost your agency time and money in repairs. See How Plowing Damages Roads, and 3 Ways to Prevent It.

How to measure the attack angle

You can check the angle with a magnetic angle finder. It’s an inexpensive dial gauge sold at hardware and industrial supply stores. Park on level pavement with the blade down, then set the finder’s magnetic side flat against the angle iron. The angle iron is the steel bar the cutting edge bolts to. Then read the angle on the dial.

If the angle is off, adjust the plow using the maker’s instructions and measure again.

Before the season

Park on flat, level pavement with the blade down.
Measure at the angle iron with a magnetic angle finder.
Set the plow to 65° unless your edge or surface calls for another angle.
Check again after you change cutting edges, add shoes or switch to wear bars.

Frequently asked questions

What is the best attack angle for a snow plow?

For most surfaces, about 65°. Use 55° for gravel and heavy snow, and 75° for scraping hard-pack or ice on pavement.

Can I adjust the attack angle on a contractor plow?

No. Contractor plows are built at a fixed angle. Adjusting the attack angle applies to the large highway plows that government fleets run.

How do I measure the attack angle?

Park on level pavement with the blade down. Set a magnetic angle finder on the plow’s angle iron and read the dial.