# TS riving knife



## Oldschoolguy (Nov 6, 2018)

I've heard many pros and cons in regards to using a riving knife. I hear that many contractors don't use one. Additionally, while watching Woodsmith Shop and This Old House, Norm and Tom don't use one either. If safety is such a BIG DEAL why do so many NOT use them? Comments and thoughts, please.


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## GR8HUNTER (Jun 13, 2016)

FOR ME I never used one and I think one would be a hazard for me to use now of course my old WT table saw didnt even have an option to put one on so the grizzly dont have 1 either dont forget in beginning I said for me :<))))


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## Cold_Pizza (Jan 30, 2019)

I think the same thing when I see people putting milk and sugar in their perfectly good cup of black coffee.

It's all preference.


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## runswithscissors (Nov 8, 2012)

Maybe you are confusing blade guards with riving knives. It is a time-honored tradition to throw away the blade guard as soon as you discover what a pain in the posterior it is. But true riving knives rarely have to be removed, except for dado stacks, so that they are typically not in the way. A true RK moves up and down, and tilts, with the blade, and is slightly lower than the blade, so you don't have to remove it for blind cuts. The intended function of a riving knife is to prevent kickbacks, which are the most common type of TS accident.

I surmise that kickbacks are worse with the more powerful (3 hp and up) saws that many people use today. With my dad's old Sears 1/2 hp TS of many decades ago, the user could over-power the saw if a kickback seemed imminent. Stalling the motor like this usually tripped the motor's built in overload protector. I don't miss that saw at all.

There are after market blade guards that can be used with a riving knife.

On older saws lacking a riving knife, lots of people use an aftermarket splitter, or make their own. These partly function like a riving knife, though they don't hug the blade the way an RK does.


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## MrUnix (May 18, 2012)

> I've heard many pros and cons in regards to using a riving knife.


What were the 'cons'?

Cheers,
Brad


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## John Smith_inFL (Dec 15, 2017)

I have been messing around with table saws since the early '60s.
very rarely was there a splitter or riving knife on any of them.
a splitter or riving knife will not stop kickbacks by themselves, you must have the
pawls and blade guard in place also to be totally safe.
as I got older, I "tried" to have ALL safety features in place because
I was starting to hear more and more horror stories of table saw
and workshop accidents in general.
after spending 7 days in the hospital last year from a kickback to the face,
I have become sort of an advocate for workshop safety.
because you never know when that 1/10th of a second of distraction will bite you.
have fun - play safe - work safe

.


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## Peteybadboy (Jan 23, 2013)

JS thanks for the advice.


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## Redoak49 (Dec 15, 2012)

> I've heard many pros and cons in regards to using a riving knife.
> 
> What were the cons ?
> 
> ...


Please where are the cons for using a riving knife? Could someone explain the hazard of using a riving knife? It is not in the way. It will not stop all kickbacks but will prevent a lot of them.


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## John Smith_inFL (Dec 15, 2017)

the only "con" that I have experienced with the splitter is when
cutting wood that wants to pinch after it passes through the blade.
this results in applying more pushing power which "could" present a safety issue.
other than that - I have never experienced an issue with the knife/splitter itself
being on or off of the machine.
+ 1 for "no pro or con".

.

.


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## OSU55 (Dec 14, 2012)

Having used ts' with and without a RK, I have no desire to use a ts without one. It probably accounts for 90% + of the safety improvemt of the guard pawl rk system.


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## DustyM (May 16, 2016)

The only time I'm not using my riving knife on my Delta 36-725 is when I'm using a dado stack or cross-cutting with my sled. I've definitely experience ripping thick stock that releases tension when cut (and starts to close toward the rear of the blade). It pinched on the riving knife and stopped me pushing it. Without that knife, it would have pinched on the blade…bad times for all.


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## bondogaposis (Dec 18, 2011)

I think a true riving knife would be a plus, my old Unisaw doesn't have one. I use a micro jig splitter and that works fairly well.


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## HokieKen (Apr 14, 2015)

> I think the same thing when I see people putting milk and sugar in their perfectly good cup of black coffee.
> 
> It's all preference.
> 
> - Cold_Pizza


That's not preference, that's just ruining coffee ;-)

The only "con" I see to using a riving knife is that it has to be removed to use a dado stack. And even that's more of a minor inconvenience. The only way I can see it being a safety hazard is if it's bent or positioned improperly and actually pinches the wood to the fence. If your saw has one, I say use it. Mine doesn't so I have a ZCI for use with my rip blades that has a shop-made spltter.

I'm going to agree with a previous comment too about the blade guard. Get rid of that thing. It may provide a modicum of safety in one respect but I find anything that impedes my vision of what's going on at the blade during a cut to be far more of a hazard.


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## Mainboom (Jan 24, 2019)

I always use my RK since I got my new saw. my old one did not have one. my old saw would get kick back quit often. the only time I have had kick back with my new saw is when it was a piece less then an 1/8 on the offcut side. and its only happened maybe once in a year. So there are no cons to using it. Are there cons to using safety glasses ? its about the same thing.

and as far as tommy and norm not using one. first norm hasn't had a show in like 15 years and is ill so he does not do much wood working anymore. second contractor table saws don't have riving knifes. they have the anti kickback shoe. which is part of the blade guard which is just a pain. plus just because you see someone do something don't always make it the right way. I don't care who they are. if the manual says to use a riving knife you should use it that is how the manufacture intended the machine to be used


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## Oldschoolguy (Nov 6, 2018)

Good morning friends, As to my post, I should have said excuses, not cons. Some of the excuses I've heard, is that they don't make a riving knife for thin kerf blades, too much trouble…...what!!!!!. it get's in my way…...duh!!!!!!. As for the thin kerf blade excuse, I get that one. I have a Rigid 4516 contractors saw and they don't make a thin kerf riving knife for that model, nor do they make a zero clearance throat plate either. In addition, I have to use a combination square from the back of the table to the fence to check for parallelism. The fence is junk. Anyhow, I'm extremely new to woodworking and don't have a full comprehension as to many things. That is why I ask so many (to some) stupid questions. I'm immensely grateful, humbled and appreciative of y'all.


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## BillWhite (Jul 23, 2007)

I guess that I'm in the "sissy" crowd. I use the splitter and guard on my saw unless I'm doing non-thru cuts.
Had 1 kick back MANY years ago, and don't wanna have that happen again.
Having said that, I'm also using all the safety features I can. Hearing, eye, dust, crap on the floor, fire and smoke alarms, zero clearance, etc.
Wish I had a saw with the RK, but the old Grizz contractor saw is dead nuts accurate, and powerful enough for everything I thrown at it.
Be safe all.


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## DustyM (May 16, 2016)

> I guess that I m in the "sissy" crowd. I use the splitter and guard on my saw unless I m doing non-thru cuts.
> Had 1 kick back MANY years ago, and don t wanna have that happen again.
> Having said that, I m also using all the safety features I can. Hearing, eye, dust, crap on the floor, fire and smoke alarms, zero clearance, etc.
> Wish I had a saw with the RK, but the old Grizz contractor saw is dead nuts accurate, and powerful enough for everything I thrown at it.
> ...


Bill, I think we are all more prone to take risks and write off safety concerns…until it happens to us. Heck, I've even had friends save damaged parts of their cars from an accident and keep them around, to remind them to be safe.

My worst scare (thankfully) was trying to rip 2×2 inch maple turning stock to make lathe tool handles. I was using no riving knife at that time, and could feel that pinching and grabbing the blade. I immediately slammed my thigh into the off switch, unplugged my saw, and left the shop for the day. Too much adrenaline to keep going safely.

Honestly, now I won't rip anything thicker than 5/4 on my TS unless it's for a finishing cut (in the above example, since the stock was getting turned, I really didn't need a super clean rip). If it's just rough cutting, I use my bandsaw.


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## Sawdustonmyshoulder (Jun 19, 2008)

I had a 24×24 piece of 3/4 ply come to visit me in the stomach one day because it hit the back of the blade of my old Delta Unisaw.

Next day…. Old Unisaw was on Craigslist / Facebook and I was on Amazon ordering a new Delta Unisaw with a wonderful riving knife on it. I never looked back.

The bruise was just about healed when the old saw went to its new home and the new saw was in my shop.









*Old Delta*









*New Delta*


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## Underdog (Oct 29, 2012)

> second contractor table saws don t have riving knifes.
> - Mainboom


Actually… the SawStop Contractors Saw does have a riving knife. And a quite good one too. It's easily removed and replaced.


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## fivecodys (Dec 2, 2013)

I used my saw for almost 20 years without the stock guard or splitter. 
It was a piece of junk anyway….then….. Wham! A piece of plywood kicked back at me and hit me in the stomach. I had a small gash and a huge bruise.

The next day I posted here about aftermarket splitters and guards. The comments were mixed but the overwhelming theme was "SharkGuard". 
A call to Lee set me on the path to a combination splitter/guard that would fit my saw.

It is the best modification I have made to this saw so far. It goes on and comes off very easily making it convenient to use .

It also incorporates some dust collection so that it a big plus.
I wish I would have done it years ago.










As far as "Norm" is concerned, I would bet that he would have used a riving knife if one had been available back then. He is not a foolish man.
Scott Phillips (New American Workshop) has always used his guards. Again, not a foolish man.

Me? I was foolish….. but not anymore.


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## Sparks500 (Jun 30, 2017)

Love my Shark Guard.


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## kelvancra (May 4, 2010)

My saw is only a 3 hp [cabinet saw]. Enough uummff to toss a board, such much smaller ones can. I've dealt with kickbacks, but was fortunate avoiding calamity.

I started looking for solutions to boards pinching the back of the blade and learned about after market splitters. I dropped the money for one and, after installing it, catches and kickbacks are all but gone (since the wood can't pinch the back of the blade).

I have had to flip a board, because of how tight it was pinching the splitter. When the kerfs met and the 2x separated, it's with a crack.

My saw didn't have a riving knife, but it did have the usual "one size fits everything" thing. When they were selling, I bought a Merlin Splitter [after learning a bit more about them].

It's pretty simple you need an access hole about 1/2" in diameter to poke a screwdriver through and against the button and it can be removed in about fifteen seconds, or less. It goes back on even easier.

This was $200.00 several years ago. It remains worth every penny. As such, I'd say get one of some kind, if your saw doesn't have a splitter or riving knife.



> the only "con" that I have experienced with the splitter is when
> cutting wood that wants to pinch after it passes through the blade.
> this results in applying more pushing power which "could" present a safety issue.
> other than that - I have never experienced an issue with the knife/splitter itself
> ...


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## OSU55 (Dec 14, 2012)

> second contractor table saws don t have riving knifes.
> - Mainboom
> 
> Actually… the SawStop Contractors Saw does have a riving knife. And a quite good one too. It s easily removed and replaced.
> ...


As does the Bosch 4100


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## Oldschoolguy (Nov 6, 2018)

Hey Mainboom, I've been watching This Old House lately and Norm is present on the the show. I watched him several years ago on The New Yankee Workshop and he didn't use one then either. Maybe they didn't make RK for cabinet saws back them. Furthermore, my owners manual for said contractors saw, specifically states, and shows a definitive picture of how to change a RK. I don't mean to sound either condescending nor patronizing. I wish to continue to use this forum as a much needed learning experience and make friends, not to alienate them. Hope, that you and I can be mutual friends and I positively do appreciate ALL your feedback. Hope you have a great day.

Regards,
Floyd Mills
Lexington, NC


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## runswithscissors (Nov 8, 2012)

If your saw's manufacturer doesn't have a thin kerf riving knife available, it's easy to make one. 14 gauge steel is the right thickness. Lacking that, the body of a retired saw blade will work fine. Use the standard kerf knife as a pattern, and cut out a new one. Easy peasy.

As for an RK being a disadvantage when the wood pinches down on it (meaning you have to push harder), that's exactly what it's supposed to do. I just back off the cut, and start it again. The new kerf you're making is usually enough to remove the reaction wood so that you can complete the cut safely.

All table and bench saws now, including job site and contractor's, are mandated to have a riving knife.


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## pintodeluxe (Sep 12, 2010)

Anyone that has a good riving knife on their tablesaw is using it. Now I'm not talking about a flimsy splitter attached to a blade guard that was standard issue on saws for decades. A good riving knife that raises and lowers with the blade. There's no reason not to use it for a majority of cuts. On the Sawstop especially, it takes two seconds to put it on.

Avoid kickback and spoiled cuts, and use the riving knife if you have one.


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## Oldschoolguy (Nov 6, 2018)

Hey runswithscissors, thanks for the tip and info. How much thinner does the RK than the blade have to be? Also, do you go by the kerf or the saw body?


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## runswithscissors (Nov 8, 2012)

The RK should be no thicker than the kerf. Thinner is not a problem. Of course, if you use an old blade to make one, the body will be thinner than the kerf. Though I haven't measured, the body of an old full kerf blade might be about right for a thin kerf RK. You could use a micrometer to determine this.

Also, I don't see why a riving knife would interfere with a cross cut sled. A splitter, yes, but a true RK is no higher than the blade, regardless of blade height. Should be slightly lower, actually.


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## Mainboom (Jan 24, 2019)

ill just shut up then…... ALIENATED


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## DBDesigns (May 29, 2018)

My TS is an old Jet Super Saw .(Not so super) It came with a contraption that didn't work very well and frankly was more dangerous than not having one. I would love to have a decent RK on the saw but it would need to be aftermarket. No blade covers allowed. Too dangerous.

Any suggestions are welcome as to where I can find one. Maybe I'm not looking hard enough on the INTERNETS but I have to have thin kerf, can't part with my current saw, and don't have time to fabricate one. That Shark Guard has a lot going on above the saw and looks ungainly. I don't need overhead dust control and it will be in the way in my small space.

I still have all of my appendages and I intend to keep it that way. I have gotten very aware of safety in my old age so this is a very good discussion.
Any help?
Best,
Tim


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## fivecodys (Dec 2, 2013)

> That Shark Guard has a lot going on above the saw and looks ungainly. I don t need overhead dust control and it will be in the way in my small space.
> 
> I still have all of my appendages and I intend to keep it that way. I have gotten very aware of safety in my old age so this is a very good discussion.
> Any help?
> ...


You can buy the shark guard without the dust collection port.

http://www.thesharkguard.com/


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## RonaldW (Aug 3, 2018)

I find a splitter does the job well, however my Delta Unisaw can only accomodate the splitter for 90 degree cuts. It doesn't angle with the blade for other cuts


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## runswithscissors (Nov 8, 2012)

See my "riving knife for unisaw" blog. I have made a true riving knife that works on older Unisaws. I made up about 15 of these, and have 3 or 4 left. Didn't sell like hotcakes, obviously, but so far no-one has reported that they don't work as promised.

Others have done this as well. There are several good designs out there. "Ttalma" has a nicely designed one, for example, though his is for a 12" saw. Mine is not a thing of beauty, but it does function, and can be installed without removing the top. Shark Guard has a good looking one for the Unisaw, though it isn't quite a true riving knife (has to be manually adjusted for varying blade heights).

When mine are all gone, I'm hoping that someone will take it on. At this time, it is way too labor intensive to take any further. But I'm convinced the principal parts could be die cast to great advantage. Trouble is, the dies are very expensive, and you'd have to have a pretty solid market for it to work out. Speaking of which, the problem with any aftermarket RK is that the market will be a steadily shrinking one, as old saws are retired to be replaced by new ones with the currently mandated RK. On the other hand, there are still a heck of a lot of old Unisaws, and others, out there. Hundreds, at least.

I wonder if anyone has designed an RK for older Powermatics, Jets, and Generals, etc.?


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## Stowerscw (Jan 15, 2018)

I was under the impression that riving knives didn't start coming on table saws until relatively recently. I know mine doesn't have one and I think it was made in the 90's. Maybe that's why all the "old" woodworkers don't use them?


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## runswithscissors (Nov 8, 2012)

I believe new saw designs beginning about 2007 were required to have the RK, and that saws already in the pipeline could be sold without one for another couple of years or so. So yes, I think your are right about old woodworkers still using saws without one because their saws are old. There is no advantage to not having a riving knife that I can think of. They really do go a long way toward preventing kickback.


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