I’ve been kicking this can down the road for years, but I finally got a job that involves cutting so much melamine board there’s no way I’m doing it with a circular saw.
I watched multiple safety videos before even opening the package, and now I’m just sitting here staring at it wondering whether I should fire it up and cut off a finger or two. I’m fucking terrified of this thing.
Based on the context in the video, it seems like people remove it. Why?
Well there’s lots of reasons why you might.
On my table saw, you have to remove the riving knife to install the blade guard and splitter. They plug into the same port.
You can get wide and narrow riving knives for my table saw to match wide or narrow blades.
On my table saw, the biggest reason I remove my riving knife and run it without is for dadoing. A standard saw blade is 10 inches in diameter, a dado stack is 8 inches in diameter. The riving knife is too tall. On my saw it has to come out for dado use, on others it retracts. It’s not hard to forget to reinstall/extend it.
Sometimes you’ll use a table saw with jigs or fixtures that would interfere with the riving knife, so you remove it. In those
You’ll also see folks remove it for use with a zero clearance insert. There’s a large hole in the table top that the blade comes out, it has to be fairly large so you can change the blade. Most of it is filled with a removable plate called the throat plate or table insert. PLastic or metal ones have fairly large gaps around the blade which can present a problem, thin offcuts might fall in there. So folks will make them out of wood, and simply raise the blade through it with the table saw running to cut the slot for the blade. Well the riving knife won’t cut its own hole. So you either have to do that some other way or do without.
Oh, it’s worth mentioning: Riving knives have only been required equipment on new table saws since 2003, in the US at least. A lot of table saws out there don’t have the provision to install one.
Ah, very interesting. At some point I’ll clear room and take my dad’s saw. That predates 2003 for sure, but I remember it having a flappy clear cover over the saw and two serrated tails to prevent material slide back (not sure if that’s also kickback). It mounts into where the riving knife would be and I assume it’s mount is, effectively, a riving knife itself. We never did fancy work though, just plywood shelf cutting (now replaced with a battery circular saw) and ripping 2x4s like idiots.
That blade guard almost certainly mounts to a splitter, which does pretty much the same job as a riving knife. The technical difference is a splitter is mounted to the table, a riving knife is mounted to the motor/blade assembly. Those serrated tails are called anti-kickback pawls, they are indeed meant to arrest a board (sheet, really) during a kickback by digging into the stock by digging into it.