What is a brush cutter blade?


What in the world is that? It’s a brush cutter blade!

It looks like something James Bond might have hurled at his head. They come in several sizes and shapes, but they all have one thing in common. When the nylon line in your trimmer head just won’t “cut it”, it might be time to consider a brush cutter blade.

Not for the faint of heart

Brush cutter blades are an aggressive option for removing heavier growth. Emphasis on aggressive. Much like a chainsaw, there is very little room for error. Not to beat a dead horse here, but if the horse is dead, there’s a good chance it was killed by a brush cutter blade so let me just say this one more time… brush cutter blades are dangerous, accidents happen, Be careful!

I want one! I want one!

Slow your roll there partner, the brush cutter blade is not for every straight shaft trimmer. There are a few things to cover before you attempt to mount a brush cutter blade:

How’s it all work, man?

Your trimmer has three basic sections, the engine, the shaft and the head. When the engine runs, it causes the shaft (which is inside of that long metal tube) to rotate. The shaft causes the trimmer head to oscillate and the protruding trimmer line cuts the grass.

Now, imagine removing that trimmer head at the bottom of the shaft and replacing it with a steel Frisbee, with teeth sharp enough to remove your foot in record time. That’s the brush cutter blade.

These blades require very specific hardware to install them properly and this is important because the last thing you want is for one of these things to fly off of the end of your trimmer! Just ask my friend “stumpy”. We call him Stumpy cause he tried to attach a brush cutter blade the wrong way and that makes him dumb as a stump.

So, really the next question is “Can I use a brush cutter blade with my trimmer?

By the numbers

When it comes to using a brush cutter blade, there’s really only one significant difference and it has to do with the strength of the shaft.

Some trimmer shafts are a solid metal rod which can handle a significant amount of torque and resistance. These are found in some straight shaft trimmers and they are ideal for brush cutter blades.

Most shafts, however are comprised of a twisted steel cable. They are more flexible than the solid metal shaft, but are rated for less resistance. These are more prone to fray or break if they are required to turn something like a brush cutter blade. If you have a curved shaft trimmer, you have one of these drive cables.


To install a brush cutter blade, first you must be able to remove the trimmer head and mount the blade onto the bottom of the shaft the proper way. I said “Proper“. Let me say it again…..PROPER.

Some trimmers come with a trimmer head that is unique to that trimmer alone. These heads are not designed to be removed and replaced by anything other than the exact same head that came with the trimmer to begin with. If this is the case, your trimmer is not designed to use a brush cutter blade.

Other trimmers are more “replacement friendly”. The original trimmer head can be removed from the shaft and replaced, either with the same head or upgraded with a similar replacement option.

And still others may be what has commonly been referred to as a Power Attachment System. The P.A.S is a two cycle engine unit mounted to a half-length shaft. At the end of the shaft is a coupling that will connect the engine to a multitude of lawn-care attachments such as a brush cutter blade.

The second consideration is whether the appropriate mounting hardware is compatible with your trimmer. The mounting hardware can include a “blade adapter”, a retaining ring or lock washer, the right sized mounting nut as well as a whole slew of safety equipment.

Safety Safety Safety Safety Safety

Manufacturers of brush cutters highly recommend that you outfit your trimmer with a handle kit. The handle kit is simply a handlebar that mounts cross ways against shaft tube, allowing the operator better control while operating the machine. This is important, as the very weight and movement of the blade can completely alter the dynamic of the machine.

While the little, plastic trimmer head would buzz along at the bottom of the shaft with little effect on the direction the head would travel, the steel brush cutter blade can cause pull and drag in unforeseen directions, not to mention the kick-back effect of striking heavier brush or unseen objects.

The ability to control the blade during cutting is essential.

Many of these kits will also include the right deflector shield (a must have, unless you enjoy blindness and/or concussions), a cutting spacer bar (to keep from accidentally removing the neighbors fence post) as well as a shoulder strap (which supports the weight of the machine, freeing both hands to control the cutter) and a whole slew of safety devices (goggles, caution signs, etc).

Pretty please. With a cherry on top.  Use the freakin’ safety devices.

Is it cheap? Not always. Is it necessary? Yes. Do I like posing rhetorical questions to make a point? Sometimes. But the question you should be asking yourself is not “Can I afford to get this?“, but rather “Can I afford not to?

There really is no going back from a brush cutter accident. 22 steel teeth will not forgive you and if you cut corners and the moment you forget to respect the brush cutter blade, it will let you know.

Be safe.

Which blade to choose

What you’re cutting is the single, most important factor in choosing your blade. Blades come in nylon or steel. There are flail blades and multi-tooth saw blades. There are blades designed to lay down leafy, ditch weed and blades designed to take down saplings. Just like picking a trimmer rather than a reciprocating saw to trim your weed, its important to choose the right blade for the job.

Here are a few:

GENUINE ECHO 69500120331 8″ 80 TOOTH BRUSH CUTTER BLADE: This blade is constructed of high quality, heat treated steel and is ideal for clearing large areas overgrown with a mixture of foliage.

STENS 395-129 STEEL BRUSHCUTTER BLADE 12″ X 3 TOOTH: Designed primarily for grass removal, the three steel blades have a combination of cutting and ripping that will clear the area in no time.

GENUINE SHINDAIWA 80424 BRUSHCUTTER BLADE, 9″ 24-TOOTH MAXI BLADE: this is a more aggressive blade, designed for for cutting undergrowth and thinning small saplings.

So, there you have it. Lot’s to consider, lot’s to choose from. When in doubt, consult your local dealer and make sure you do it right the first time.

Seems pretty “clear cut” to me. HA!


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Bill Brown

Bill is the head of content creation for the LawnMowerPros Blog and DIY section. He’s been in the Outdoor Power Equipment Industry for years and he’s still learning new things everyday. You can often find him creating featured articles, DIY guides, videos, graphics and much more.