Imagine a solid chunk of walnut falling from a ten story building.
Now imagine catching it with your face. It wouldn’t be fun — just ask Cardboard Danny DeVito (may his paper soul rest in peace).
Kickback from a table saw is even worse — and it happens faster than you can blink.
But don’t put your saw on Craigslist just yet. Kickback is easy to avoid — as long as you understand why it happens and take the right precautions to prevent it.
So to help you stay safe in the shop, I’m going to cover everything you need to know about kickback, including:
I’ll go into more detail below, but you can use this list as a quick reference now and in the future.
✘ DO NOT
✓ DO
Table saw kickback is when the blade launches, or “kicks back,” a workpiece or offcut towards the front of the saw (where the user is standing).
Because of how fast a saw blade spins, this can happen in a fraction of a second (.0035 seconds, for example) — and it can do a lot of damage to you and your shop.
Kickback isn’t unique to table saws. It can happen with handheld circular saws and chainsaws too. The difference is that on a table saw, the lumber itself becomes a dangerous projectile.
There are 3 basic causes of table saw kickback:
If your rip fence isn’t set up properly, or if you use it for the wrong type of cuts, your stock can get pinched between the fence and blade.
This is NOT GOOD. If the board binds, the blade’s going to push it back with more force than you can push it forward.
Potential Causes:
If a board doesn’t move through a cut in a straight line, it can drift over the back of the blade.
When this happens, the blade’s back teeth start to lift the board until it gets launched over the top of the blade like a slingshot.
That’s why it’s essential to push the board down into the table and flush against the fence while ripping. This helps stop the board from lifting or drifting over the blade’s back teeth.
Potential Causes:
As a board is cut, the kerf can squeeze together and pinch the blade — which binds up your cut.
And when wood binds around the blade, it’s liable to kickback. If you feel like you have to put too much pressure into a cut, turn off the saw and figure out what’s wrong.
Potential Causes:
For one, sudden movements around a running table saw are never ideal.
Kickback can push your hand or fingers into the blade before you have time to react.
But the most common danger of kickback isn’t actually the blade.
It’s the wooden missile flying towards you.
We recently rented the Phantom TMX 7510 — the best slow-motion camera on the market — and were able to get never-before-seen footage of real kickback in action.
This allowed us to calculate how quickly kickback sends a block of wood flying — and how much force is behind it.
So, exactly how powerful is kickback?
With the help of my friend Jens Fehlau from Flammable Maths, we studied footage of a 1.5 lbs (.7 kg) hunk of walnut being launched by my table saw.
We figured out the board had an acceleration of roughly 3,211.94 ft/s2 (979 m/s2). Using that variable, we calculated a force of about 646.53 newtons.
That’s around 141 lbs of impact force.
Obviously, this is rudimentary physics since we assumed linear acceleration.
But the point is, it's more than enough to cause significant damage to the user — and potential hospitalization.
Kickback is no joke. And that’s why you NEVER want to do any of the kickback “triggers” below.
These table saw no-no’s are the quickest ways to experience the full wrath of kickback. DO NOT MAKE THESE MISTAKES.
Making a free-hand cut on the table saw means you’re not using any sort of guide or reference to push your stock through the blade.
Even if you’re the Dumbeldore of woodworking, don’t do this.
You’re only human — and if your cut isn’t perfectly straight, the board is liable to drift over the back teeth and launch straight at you.
Some people claim free-hand cuts are no big deal because they “know what they’re doing.” They may be great woodworkers — but they’re also being reckless, and have gotten lucky so far.
No matter how small the cut, always use a guide with your table saw. Miter gauges, crosscut sleds, rip fences, or jigs of your own creation — they all work.
You’ll not only get better cuts — you won’t have the Grim Reaper peeking over your shoulder every time you switch on the saw.
Remember the #1 rule about rip fences:
Only use a rip fence for boards that are longer than they are wide.
Otherwise, use a miter gauge or crosscut sled.
Pushing the shorter side of a board along your fence increases the chances of that board rotating and drifting over the blades back teeth, or binding between the blade and fence.
Some people do this inadvertently on their crosscut sled. They need to make repeatable cuts that are too long for a stop block on the sled, so they use the fence as a stop block—bad idea.
Here’s the right way to use your fence as a stop block:
Clamp a block of wood towards the front of your fence, and use this as the stop block for your stock. Hold the stock in place as you push the sled forward.
The edge of your stock should be completely clear of the stop block by the time it reaches the blade. This lets you make quick, repeatable crosscuts without the risk of binding.
Featherboards are a great tool for making safe cuts on the table saw — as long as you’re using them correctly.
Here’s the most important rule about them:
Make sure your featherboard is NOT set up past the front of the blade.
If it is, it can push your offcut, causing it to pinch the blade or get lifted by the teeth. Either way, it’s a kickback generator.
Place your featherboard 100% in front of the blade, and you’ll be good to go.
Kickback happens in milliseconds — but you can do a lot to avoid it with a minute or two of preparation before cutting.
As with most tools, a big part of table saw safety is what you do before turning it on (take note, ladies and gentlemen).
The whole point of using a rip fence or crosscut sled is to guide your stock through the blade in a straight line.
But if your lumber isn’t made up of straight lines — as in bowed, twisted, or cupped — it can be a problem.
Make sure your stock has a square, jointed edge for riding along your fence, and at least one planed face that lays flat on the table.
(If you don’t have a jointer, here’s a few other ways to joint a board.)
It’s also important that your stock is acclimated to your shop. Well-acclimated lumber is less likely to pinch the blade during a cut. Let it sit in your shop a few days before milling.
Imagine you’re ripping a board. What would happen if the far side of the fence was closer to the blade than the front?
Obviously, your board could get pinched and bind between the fence and blade. And you know where that leads.
Making sure your fence is square is a crucial part of table saw maintenance, and you should always double check with a trusted square before cuts.
If you only take away one thing from this article, it’s this: USE A RIVING KNIFE.
Riving knives do an incredible job of preventing kickback.
For one, they keep your stock from drifting over the back of the blade and getting lifted by the teeth. They also stop the kerf from pinching the back of the blade.
These simple devices have been standard on all table saws since around 2007.
If you have an older table saw, it might be equipped with a splitter. These aren’t as good as riving knives (since their height doesn’t adjust with the blade), but they’re better than nothing.
Blade guards cover the top of your blade, ensuring your stock can’t fly up at your face. They also keep your fingers from getting pushed into the blade — a common kickback-related injury.
You’ve probably also seen the anti-kickback pawls that attach to your blade guard or riving knife. Their jagged teeth drag over the outfeed side of your stock, hooking into it if there’s kickback.
Some table saw blades come with anti-kickback shoulders as part of their tooth design.
Several of the CMT blades we carry include this feature — and yes, they’re fully approved for use on SawStop table saws.
BUT I SAW THIS GUY ON YOUTUBE…
Let me address the elephant in the room.
You’ve probably seen countless videos of woodworkers using a table saw without any of these anti-kickback devices.
Maybe you’ve even read comments in the swampy corners of online forums where people brag about never using a riving knife because they “know what they’re doing.”
Did you know people fought against seat belts when they were first put into law? They probably also “knew what they were doing.” Don’t be that person.
It’s true that you can’t always use a blade guard or anti-kickback pawls.
But at the very least, always use a riving knife.
The only time you should remove it is if you’re using a dado stack. Besides that, you can make any cut with the riving knife attached.
See you in the comments, trolls.
This is guaranteed to get some sour responses. But if your blade is set way above the height of your stock, it increases the chances of kickback.
The general rule of thumb is to set the peak of your blade about ⅛ inch above the height of your stock. That translates to the height of one tooth tip, give or take a hair.
Ripping really thin pieces can lead to your stock binding between the fence and blade.
Consider setting up your cut so your thin strips are the offcuts. And be sure to use a featherboard and a good push stick to keep your stock flush against the fence.
Take a deep breath. It’s time to conquer the beast.
The most important thing here is to focus on what you’re doing and set aside all distractions.
When your table saw is running, all that exists is you, the blade, and your piece of lumber.
Become the Bruce Lee of bridle joints.
A good push stick does more than just push your stock forward. It has a long base that lets you keep your board flat against the table and flush against the fence.
That’s why those long plastic bird’s mouth push sticks (that often come with table saws) aren't that great. They only let you push forward, without any way to keep your board from lifting up or drifting over the back of the blade.
Also, your fingers are less likely to get thrown into the blade if you're using a push stick.
Just make sure the heel is in good shape, as these can get chopped away over time.
A general rule of thumb (and pinky) for when to use a push stick:
Splay your fingers as wide as you can. If the distance between the tip of your thumb and pinky finger is MORE than the distance between your blade and fence, use a push stick.
We have a great heavy duty push stick available in our store, as well as free plans for making your own push stick at home.
Remember that you want to put pressure on your stock in 3 directions:
It doesn’t need to be heavy pressure — just enough to make sure everything stays flush.
It’s tempting to keep your eye on the blade while making a cut.
But if you’re ripping, it’s actually safer to keep your eyes focused on where your lumber meets the fence.
This makes it easier to keep your stock flush against the fence, which helps prevent kickback and gives you cleaner cuts.
The cut isn’t finished until your stock is past the back of the blade.
Sure, technically it’s finished before. But pushing your stock all the way through really reduces the risk of kickback.
Set yourself up with an outfeed table, even if it’s a makeshift one. A couple saw horses and a piece of MDF will do the trick.
If you follow the steps above, your chances of kickback will be minimal.
But the unexpected is, well… unexpected. And at 56 feet per second, not even Patches O'Houlihan could dodge these murder missiles.
Here’s how to keep safe if the unexpected happens.
When we did our kickback experiment with the slow motion camera, some pieces of wood went high, some went low — but every single piece flew towards the front of the saw.
Whenever you’re making a cut, stand to the side of your stock, so you’re not in the line of fire. For rip cuts, stand on the opposite side of the blade from the fence.
And use a push stick, so you don’t have to lean over the blade.
Kickback is scary powerful, and personal protective equipment (PPE) isn’t going to stop it from hurting — but it can do a LOT to prevent more serious injury.
Always wear eye protection. If you happen to take a piece of walnut to the face, a thin layer of plastic slowing it down is better than nothing at all.
Also, a good woodworking apron can be a torso-saver.
I can’t tell you how many messages I’ve received on Instagram from people telling me their Katz-Moses apron protected them from what could have been serious kickback damage.
We even tested the apron on a ballistics gel dummy. The difference was a 4-inch gash without the apron, and no broken “skin” with it on.
I’m not telling you this to say “my apron is the best” (though it may be).
Whatever brand you choose, just make sure it’s made out of a thick, durable material like canvas or leather.
Our aprons are made from 20 oz waxed canvas — and ready to keep your belly safe from rogue blocks of wood.
While table saw kickback is a serious risk, you have the power to keep it from happening.
The most important thing is to be focused, aware, and cautious. If something feels wrong, or you have to force your stock through the blade, turn off the table saw and reevaluate.
Remember: If you treat your table saw with respect, it’ll give you the efficiency and accuracy you're after.
And put the freaking riving knife back on.
Almost every woodworker has a kickback story — what’s yours? Share it in the comments below!
Follow us on Instagram @katzmosestools and check out my YouTube channel.
And as always, STAY SAFE IN THE SHOP!
Brendan
February 06, 2022
I am fortunate to have not experienced kickback yet, but a friend of mine did.
A few years ago when I was in art school, I walked into the bathroom and saw my buddy, shirt off, looking into the mirror. He had a welt the size of a soft ball dead center on his sternum, he was ripping pine 2×4’s and one kicked back and speared him in the chest. He was fighting back tears and the winces of pain as he explained to me what happened. There was a little bit of blood, but no major cuts, just a huge DARK black/blue/green bruise. Looked extremely painful. I believe he only had a t-shirt for protection. Scariest part was imagining if it hit him 4-5” higher, it would have been straight into his neck. That would have surely put him in the ER. That was early in my wood shop days, and even though he has my sympathy, I’m grateful I got to see the damage these tools can do early on. I promised myself I would ALWAYS be as cautious and informed as I can be moving forward after seeing that.
Thank you Jonathan for the great content and tips, and for helping to keep people safe! Your videos are fantastic.