Brush cutter, strimmer and trimmer: what is the difference
The names overlap, and they change between countries. In general, a string trimmer (called a strimmer in the UK) uses a spinning nylon line to cut grass and soft weeds. A brush cutter is a heavier machine, often with a stronger engine or motor and a bar or loop handle, and it can take a metal blade for tougher growth. Many machines sold as brush cutters can also be fitted with a line head, and some trimmers cannot take metal blades at all. Always check your machine’s manual to see what it is approved for.
Nylon line and other non-metal cutting heads
A nylon line head is the usual choice for lawn edges, around fences and walls, trees and rocky borders. The line is flexible, so it is less likely to damage surfaces or to kick back when it hits an obstacle. It copes best with grass and soft weeds, and is less effective on thick or woody stems.
Grass blades
2-tooth and 3-tooth blades
These metal blades have a small number of large teeth. They tend to be used for tall grass, weeds and light brush in open areas. A 3-tooth blade is often described as a balance between speed and cutting power for dense weeds.
Knife or star-shaped blades
Lightweight blades with several pointed arms. They are sometimes suggested for soft stems and light trimming. They can dull or chip when they strike hard objects such as stones or fence posts.
Multi-tooth blades for thicker growth
Blades with four or more teeth are generally positioned for dense grass, heavy weeds and thicker undergrowth that is not yet woody. More teeth usually means a smoother cut at the cost of needing more power, so check what your machine supports.
Saw-style and chisel-tooth blades for woody growth
Circular-saw-style blades with many teeth are designed for brambles, thick stems, bamboo and small saplings. Teeth counts vary widely between models, and so does the stem diameter a blade is rated for. Follow the manufacturer’s stated limits. Using a blade beyond what the machine and blade are rated for increases the risk of kickback and injury.
Carbide-tipped blades
These have tungsten carbide tips on the teeth, which usually stay sharp longer than plain steel. They are used for heavy clearing of tough brush and semi-woody stems. They cost more, but may suit regular, heavy-duty use. They can still be damaged by striking rock or metal.
Quick selection table
| Vegetation | Blade type to consider |
|---|---|
| Soft grass and lawn borders | Nylon line head, or a light knife blade if your machine supports it |
| Tall grass and thick weeds | 3-tooth or multi-tooth metal blade |
| Brambles and woody shrubs | Saw-style, chisel-tooth or carbide-tipped blade |
| Small saplings | High-tooth saw-style blade rated for the job |
Compatibility and safety
- Match the machine: check the maximum blade diameter, arbor (center hole) size and rotation speed in your manual. A blade must be approved for your machine.
- Use the guard: metal blades normally require a specific guard, and a line-head guard is generally not adequate for a blade.
- Wear protection: eye or face protection, hearing protection, sturdy footwear and appropriate trousers are standard recommendations.
- Mind the kickback zone: blades can kick back when they bind or strike something solid. Follow the cutting-area instructions in the manual.
- Clear the area: stones, wire and debris can be thrown. Keep other people and pets well away.
- Switch off first: stop the engine and disconnect the spark plug or battery before changing a blade.
If you are unfamiliar with a machine, read the manual in full and consider asking a dealer for a demonstration. For a broader look at long-reach cutting tools, see our guide to long handled garden tools.
Sharpening and replacement
Dull blades tear rather than cut, load up the machine and can be more dangerous. Some blades can be sharpened with a file by following the manufacturer’s tooth angles, but carbide-tipped and heavily damaged blades are often better sent to a professional or replaced. Replace any blade that is cracked, bent or missing teeth. Keep blades clean and dry to limit rust.
Frequently asked questions
What are the different types of brush cutters?
They are commonly divided by power source (petrol, battery or electric) and handle style (loop handle or bike handle). Blade choice is a separate decision, covered above.
What is a strimmer used for?
A strimmer cuts grass and soft weeds with a spinning line, especially in places a mower cannot reach, such as edges, slopes and around obstacles.
Can I fit a metal blade to any trimmer?
No. Many light trimmers are designed only for line heads. Use only blades the manufacturer approves for your model.