When cutting a board on the table saw the workpiece can sometimes be flung away from the saw at great (and dangerous) speeds.
What techniques or equipment can reduce the chances of kickback?
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Riving knife! That's the best method. I've heard it said that it's impossible to have kickback with a riving knife.
Other things to consider:
Edit: One other thing to consider--I generally use two pushsticks like Mattias Wandel (https://www.youtube.com/watch?v=gdIQY_7T26k) so that keeps me on the side of the piece rather than behind it. That way, if kickback does happen, I'm out of harm's way.
Edit #2: I had to come back and add one more thing tangentially related to the OP. I read an article about someone using a sawstop who turned off the safety feature and lost his thumb. It looks like he was thinking about kickback (and using two pushsticks) and reached across the blade to free his workpiece. Bad idea.
Kickback can occur when the back of the blade gets pinched in the kerf, when a piece of wood is pinched between the blade and fence, or when a piece of wood is lifted off the table.
As others have mentioned, a riving knife, anti-kickback pawls, and fence-mounted featherboards help protect against kickback.
If using a table-mounted featherboard, make sure it is positioned before the blade (infeed side). If you position the featherboard alongside the blade or after the blade, the featherboard will actually cause your wood to pinch the blade and cause kickback.
Other types of equipment include fence-mounted rollers and manual or automatic feeders.
Fence-mounted rollers are similar in function to fence-mounted featherboards but also help push the stock against the fence. The rollers are typically designed to only rotate in one direction.
If you have an older saw, you may have a splitter instead of a riving knife. Although a splitter and riving knife both prevent the blade from being pinched, a splitter is always positioned at the same height, while a riving knife raises and lowers with the blade. This allows the riving knife to maintain a constant distance from the back of the blade. This means that when the blade is lowered for a shallow cut, there is a huge gap between the back of the blade and the splitter, as illustrated in a kickback incident analyzed on LumberJocks. A splitter only performs as well as a riving knife when the blade is raised to full height--which itself is considered unsafe unless you need the full height of the blade to make a cut.
There are some additional safety measures you can employ when making crosscuts.
Use a sled for crosscutting. The sled cradles your workpiece all the way through the blade and pushes both pieces past the blade after the cut.
Don't use your miter gauge and fence together. If you want to use the fence as a stop to cut off consistent lengths, clamp a piece of wood to the fence before the blade (on the infeed side). This way, the cutoff cannot be trapped between the blade and fence.
Before you make any cut with any power tool, you should carefully think through the entire cut, from start to finish. Some of the concerns mentioned below can directly contribute to (or prevent) kickback, but all of them are important.
Although it doesn't necessarily do anything to prevent kickback, you should always try to stand clear of the likely path of a kickback. In particular, stand off to the side of your workpiece if possible, and if you're using the fence do not stand in the zone between the blade and the fence.
As a secondary safety measure to @dfife's excellent riving knife suggestion, anti-kickback pawls are another option.
Generally they install on the riving knife itself, and are spring loaded to stay in contact with the workpiece. Think of it as a one-way clutch for your lumber.
Note that I've had issues with these scratching softwoods like pine, so I only use them if I'm still planning on heavy sanding or planing afterwards.
Keep the larger piece between the blade and fence, and push on that with your push-stick. Most kick-backs I've seen were when a narrow piece was pinched between the blade and fence. And don't stand behind the piece!
Be extra careful twisted or knotted lumber that may have alot of internal tension - much more likely to pinch & kick back.
Originally posted as a Q&A, but marked as duplicate.
Aftermarket riving knives tend to range from unavailable to sub-optimal.
The function of the riving knife is to keep the wood from catching on the rising teeth of the blade. This can happen either through operator error, or from the wood springing to a new shape with the creation of the kerf.
Splitters do this too, but are usually further from the blade, and cannot be used with tilted blades.
I had an old rockwell-beaver with no guard, no splitter, no riving knife. I still have all my fingers. Large collection of push sticks, and about two pounds of paranoia, and NEVER stand in the plane of the blade.
If your fence is set up with a track for jigs, you can get wheels that are slightly out of line, and are spring loaded. They ride up on the board, and will pull the board toward the fence. This reduces the chance of the kerf catching on the rising blade.
Couple this with a feather board. The most common style locks into a miter guage slot. There are some slick ones now that have releaseable magnet hold downs, and can both push in and down. This ensures that the board is tight to the fence at the start of the cut. Featherboards can also be mounted on the fence to push down
You can also get pawls that attach the the fence. This only engages if you have kickback, and does little to prevent it from happening in the first place.
Finally: The best safety accessory is the one between your ears.
When it comes to table saws I always say when and not if you cut something off. I think they are the most dangerous tool ever made. I know people who have cut off fingers or thumbs on chop saw and even a portable 7 inch circular saw and those are not as dangerous as a table saw. I can make almost any cut without a table saw so I almost never use a table saw and if I have to I use a table saw I use a 4 foot long push stick that I made to keep my hands at least 2 feet from the saw blade. I never put my hand over the table at all when the saw is on. In high school woodshop we had to get 100% on the safety test or were not allowed to use the table saw. The end of the first month a student cut a finger off on the table saw. I know a lot of people who lost fingers to a table saw. One cabinet maker lost three fingers on one hand and another cabinet maker had his big toe removed and put in place of the thumb he lost to the saw. My cousin is very dangerous and never follows any safety rules with the saw and said he use one all his life and never had a problem. I asked him if he knows anyone who has had a problem. He said his son lost a finger a few years ago (doing what his dad his did I think). A picture framer I know had a glove on that got caught in the blade and pulled his thumb in. Before that happened, I tried to get this picture framer to make me a special push stick and we could get them to people we know who use table saws. He said he was too busy and would not even make me one or for himself. Even after this he still is not interested in working with me to make a set of push sticks. Another fellow had turned off his chop saw and it was still slowing down when his grandchild ran up behind him and distracted him. When he turned around his thumb hit the blade and cut his thumb off. A construction carpenter had his table saw sitting on the ground with the red safety switch hanging out by the wires. I told him we should fix that and set it up as I thought it was dangerous that way. He said he had use it that way for a long time and did not have time to fix it. I would not have charged him to help him fix it. The next time I talked to him he had cut off a finger in the saw. This is only a shot list of the people I know and who have rejected any help from me or my ideas on how to use a table saw. I am 65 years old and still have all my fingers and toes.