How Chainsaw Protective Clothing Works

How Chainsaw Protective Clothing Works

It's called Engtex. Saved my ass leg once.

It should also be noted that this type of safety gear will NOT work with electric saws. This is why electric saws are so dangerous. They defeat most safety gear being that they have nearly full torque at 0RPM.

This would have been useful, in so many fucking horror movies..

This is my understanding:

An electric saw has nearly 100 percent torque all the time within its rpm range, making it much more powerful at slower speeds, probably allowing it to power through those fibers.

A gas powered saw has a regular engine, which has a torque curve. This makes certain rpm ranges have lots of torque (to cut logs) and other rpms have very little torque; allowing the fibers to slow down the chain, to a low torque rpm range, ultimately overpowering the engine while it has less amounts of torque, causing the cutting chain to stop.

However I do not know if this would stall the engine, or if a manual kill switch needs to be used?

Source: Avid RC enthusiast that owns Gas and Electric powered cars.

Less of the pain in the ass than learning how to walk with a prosthetic leg.

No joke!! i swear by these pants!

My first time cutting trees i was told wear these, i didn't think anything would come of it.

Id hit the chain brake within seconds every time!

The one time i stuttered to hit the brake, i lowered the chainsaw and it dug into my thigh and instantly ripped my pants to shreds.

I thought for SURE my leg was mangled and severed, everything happened so quick, like nothing ive experienced before.

i was scared shitless i couldn't even look down at my leg, these things do what they're designed to do and shit happens!!

The Texas chainsaw massacre guy woulda been pissed


Why are you constantly chainsawing your legs?

Can confirm. Works well. Also, it's a pain in the ass to get all that kevlar out of the saw.

You don't wear it everywhere. You wear it on your legs, in chap form.

There's probably protection for arms too, but I've only seen people wearing chaps. I have done a lot of work with chainsaws, and only used chaps.

At full speed, the chain is moving about 70mph.

The operator's manual should always be referred to just like that; operator's manual. Calling it the "owner's manual" is incorrect and Stihl lost a court case because it was assumed that only the owner needed to read the manual.

Original chains were called "scratcher chains" because they didn't actually have cutting blades. They were basically a series of sharp points that would "scratch" through the wood.

Stihl makes their chains in Switzerland. There is a sort of test to determine dexterity and precision of the worker's hands before they are allowed to assemble chains. Most of them are women.

Stihl makes a special saw just for rescue workers and fire departments. 90% of these agencies use Stihl rescue saws. (They are badass, look up MS 461 RS)

Source: I am/was an insider.

EDIT: Grammar

The chain sprocket clutch would probably stop the engine from stalling but it will certainly stop the chain almost immediately.

You don't wear it everywhere.

Where is it inappropriate? First date at the movies? Would that be ok?

Must be hot af to wear a costume that is so thick.

I would think he'd just pick up a gun for a much shorter movie


We are Groot.

" friggin chainsaw bud...its ruined now."

Lays on the ground, bleeding out, looking at his own leg laying a few feet away from him. As he loses consciousness one final thought drifts through his mind....

At least they won't have to clean those chaps fibers out of my chainsaw.

Or an electric chainsaw

Chains are designed to 'dig'. They pull themselves through what they are cutting. So yes, you were really fucking lucky.

First time I used a chainsaw was last summer, I forgot to put on the chaps and after making a cut I lowered the saw and it made the tiniest nick on my jeans. I realised that if had kept spinning even half a second longer I could have sawed half way through my leg. Needless to say I wear those chaps everytime (I was pretty fucking terrified at my own stupidity)

Gears are metal. With enough torque you can free them up (unless the thing clogging them is metal). This stuff slows the engine down until there's not enough torque to free it, and then it stops. But electric motors can deliver enough torque at any speed to break through. It doesn't matter if you slow it down because the power output is the same.

In the gif, it slows the chain down before finally coming to a rest. Before it's fully tangled, it's still slowing the motor down thus putting the engine at a different point in the torque band. By the time it's fully engaged, the engine is too slow to power through.

Sounds like the lesser-known Canadian Chainsaw Massacre.

It's actually Kevlar. I used to wear that in special chaps when I used to log ski slopes in Colorado

Did you know the first chainsaw was electric and invented by Stihl? They worked in a similar way you described but they are massive in size and weight.

My dad had a knack for idiotic accidents. One time he was cutting 2x4s with a circular saw and held the 2x4 across his lap, standing, and ran the saw blade right across his thigh. I remember my mom screaming at him for squirting blood all over her house and calling him a fucking idiot.

Hmmm. Adding a flywheel to the electric motor could give you a torque curve. Add a centrifugal clutch after that and I bet that would work with this sort of safety gear. Might be way too heavy though.

Edit: u/KillerRaccoon and u/OSUaeronerd brought up a flywheel problem I should have thought of. My response/solution: "Ok the spinning down of the flywheel is a problem, but, if you attached the sprocket to the drive with two conical gears with a degree of motion on one axis in each, you could make it so that the flywheel disengages at high rpm. It would feel like shifting gears on the way up, but on the way down the flywheel (or hell, just make it a brake actually!) would engage and fight the drive. It would work a little bit like a cv transmission."

One time he was cutting 2x4s with a circular saw and held the 2x4 across his lap, standing, and ran the saw blade right across his thigh.

You sure he's 100% there? I mean, I'd have to try really hard to do something that dense when I'm handling something that, if handled the wrong way, could kill me.

It's either off, or it's full speed. There is no middle ground or "slowing it down" like the gif shows.

The thing will keep going at max speed till it's actually shut off.

Edit : this is ELI5, look below for a more specific answer.

Depends if you're wearing a goalie mask too.

Depends if you're wearing a

No, not even to the skin. It is 6 layers of this fabric and the chain in the gif cuts through 3-4 of them.

wait, wouldn't an electric one get its gears clogged just like the one in the gif?

Or are electric chainsaws magic?

When i was young I was on a hotshot fire crew as a sawyer (one sawyer and one swamper would cut firelines during big Forrest fires to contain them), when there are no fires we were usually clearing danger areas of trees and we also thinned trees in the winter since there are no fires then (trees that were planted to replenish where they had been cleared for logging you have to clear 8 feet around the saplings that were about 6 to 8 feet tall to ensure they get clear sunlight and grow well).

We carried big jugs of gas etc over our shoulders, had to wear hard hats and carry our drinking water as well as files etc to sharpen chains, and of course, chain saws.

unless that stuff was absolutely required by law to wear, NOBODY would wear it. it would make the work unbearable to do in the autumn and late spring. It was so stinky in the truck from everyone dying of sweat every day after work the whole thing smelled sour and it made me sick. during fire season we already had to wear special gear, i bet that shit is required now. ugh

Now add in all that heat? no fucking way I could do it. and I was in shape as a shit.

in the winter? no way, it would weigh you down, make it that much harder to walk around the mountains where there are no trails, fallen trees, brush and 4 feet of snow etc.

Things might have changed but man I can't imagine being forced to wear those

For me it would probably add more risk of heat stroke than help with me hitting my leg with my saw.

Amazingly after 5 years thinning trees neither myself or anyone on our crew had a cut accident from a saw while working in the forrest. Broken legs from falling between trees/branches? Injuries from flying bark? one guy fucking around at camp and getting a kickback that cut his face in half? yes, but during work? not a single instance. We were VERY lucky now that I look back on it. And it's even more shocking because we tricked out our saws beyond belief. bored out the cylinders, removed all safety shit and had those things running at unbelievable speeds. it was so dumb it makes me shiver a bit thinking back on it. and I was so haphazard i still can't believe i made it.

Electric motors have full torque at all speeds, whereas combustion engines only have full torque at max speed. So electric chainsaw just don't care Edit: torque not power

Yeah, but that was some years ago. Trousers of today weighs about 900 grams, with protective fabric. They are also in stretch material. Works very well!

This is why you make your teenage son read a manual before you hand his dumb ass a chainsaw, or atleast give him a walkthrough other than "press that for go." The finger tip sized rip in those jeans has become quite the reminder for me to be wise about my own safety. I've gotten away with too much by the skin of my teeth so I've been stopping to think a lot more.

this still doesn't make sense to me, it shouldn't matter whether it's going at full speed or not, the gears are clogged, it can't turn, why does it matter if an electric chainsaw can apply full force on the gear from the moment it starts? the fuel one in the gif is also going at full force the moment its gears get clogged, right?

edit: yes the question has been answered.

Basically as I understand it, a gas powered chainsaw can only apply its full force when it spinning at full speed, which is why a gas powered chainsaw would need to be spinning at full speed before one starts cutting into a tree for example.

An electric chainsaw doesn't need to be moving at all in order for the engine to apply full force, so while an electric chainsaw could start cutting when it's already pushed against a tree, the gas one would need to be "revved up" first.

So when the gears get clogged, the gas one starts slowing down which means the engine loses power, which in turn slows down the chainsaw even more, up until the engine stalls and the chainsaw stops moving.

An electric one would keep going at full force, meaning the chainsaw would slow down a lot slower, and the time difference between a gas chainsaw and an electric chainsaw coming to a halt would mean the difference between the chainsaw stopping before it hits our limbs, and the chainsaw stopping inside of your limbs.

conclusion: these clothes aint got shit on an electric chainsaw, so now I know which chainsaw I need to buy for my next massacre, thanks folks!

Sealing a wound is much easier that reattaching a hole arm.

I can confirm the speed at which chainsaw accidents happen. I had a chain break once. I didn't even see it go, and only noticed when I went to cut the next branch. I found the chain hanging in a tree just over my head.

This isn't really helpful as an ELI5 because I don't understand what torque is

Think of Torque as muscle, so like in an arm wrestle the guy with the most muscle will win, even though the arms are essentially still. An electric motor has full muscle (or strength) from a stand still. A gas engine needs to running at a minimum speed to have any muscle.

I'm going to start calling my pants arsed chaps.

I didn't know that but that's super cool! Know any other fun chainsaw facts?

If you get just a normal MS 461, it is only about $200 in parts to get it up to spec of the RS model. Just a thought.

EDIT: More like $800-$900 in parts. I was not very familiar with the new 461 RS compared to the old 460 R; I am now.

The MS 461 RS is a beast. I used one at a county level training and it was incredible. I wish my department would get one.

Just the muscle fibers.

Or bleeding out.

"Fuckin thing won't bite"

looks up


Doesn't do a very good job of protecting that chainsaw.

Frig off and let me chainsaw you


I don't even care about chainsaws and I fucking love all this.

But victims all wear bikini or naked having sex

Torque is the mechanical advantage, or maybe think of it as oomph, of a rotating shaft. You feel the torque of a rotating shaft when you try to put drag or load on it, like if you pinched it with your fingers. Two motors might be spinning at the same speed, but the low-torque one would be stopped as soon as you grabbed it, while the high-torque one would "power through" and maybe even hurt you. (Note - don't grab spinning motor shafts because someone on Reddit used it as an example.)

Chaps are all arse-less. That's like the definition of chaps.

It was a brand-new chain. Not factory-made, though (made by the local saw shop, from a spool of chain). I suspect the join failed.

They are definitely warm but I prefer wearing those over chopping a giant hole in my leg. I don't care how many accidents haven't happened all it takes is one. I'll deal with the heat over losing a leg for sure.

Might as well just put a new blade on the bar after that TBH.

I remember when I had money for RC cars 😢

Chainsaws are really fun. You should cut something sometime.

Well if I'm going to wear it on a first date I sure as shit am bringing my chainsaw too.

Horror movie psychopaths hate him!

I have never seen a chain break, and I was a logger. Any idea why? Rusty crap chain, maybe? Bent bar?

Good ole stihl products. German made.

I work in wildland fire, if you run a saw youre definitely wearing chaps.

Referencing another discussion above where an electric chainsaw has like 100% torque from the start so it can rip through the clothes. A chainsaw with an engine doesn't go from 1-100 instantaneously, so that's what lets the fibers get stuck in it.

In other words, electric chainsaw would cut right through these clothes and the texas chainsaw massacre guy could keep chainsawing without compromise.

True and false. Electric motors don't necessarily have full torque at 0rpm. Especially induction motors. Check out this teardown video of an electric chainsaw:

This is trousers all rhe way, no jeans underneath.

Of course. They don't call meat hooks the "analog chainsaw" for nothing!

uh... it's not just higher. Typically, the torque on an electric motor is more or less inversely proportional to rpm. It looks more like a line than a curve, nearly completely linear with the maximum being at 0rpm.

Yes, actually.

Adding a flywheel wouldn't give it a torque curve, it would just make it take longer to spin up or down. It would actually make an electric saw better at getting through protective clothing because it would take more resistance to slow its spinning. A torque curve could be added in via the controller, though that would likely require them to install a significantly more complicated and expensive controller.