What can a Riving Knife do, that a splitter can’t do in terms of accident prevention?

[Daniel Hillmer]

I hope to understand the difference in terms of accident prevention.

[Jason Beam]

Two reasons a riving knife is better than a splitter. They are based on the following premise: Splitters traditionally have been tricky to remove (usually because they hold the pawls, guard and are held in two spots).

1. A riving knife is almost always easier to remove/replace because it doesn't house a bunch of other things. Because of this, you are more likely to PUT IT BACK ON should you take it off. Splitters are removed and left off, doing NO good at all. This is a big reason behind the riving knife.

2. A riving knife can be used during more cuts than a splitter because it sits below the top of the blade. This increases the odds that it will STAY ON the saw for more cuts. Non-through cuts, especially, since the pawls and guard aren't also hooked to 'em. Some RK's have quick-release guard assemblies, too, though.

But for me... most important is:

A riving knife sits within about 1/4" of the blade at ANY height. This means even thin stock benefits from the RK sooner. A shallow cut with a splitter can actually be a couple inches between the blade and the splitter - enough for even a little tweak, causing kickback. With a RK, the chances of twisting before reaching the protection of the RK is much reduced. :)

[John Thompson]

What Jason said under "for me". The other two I find ir-relevant as neither a riving knife or splitter does any good what-so-ever when not installed on the saw. Again.. the main advantage of a riving knife over a splitter is it is closer to the blade and moves with the blade never narrowing that gap.

A splitter is close to the blade only when the blade is basically fully raised and the gap widens as it is lowered. I run a modified splitter with crown guard and never lower my blade as it not only has a crown guard but.. a clear plastic shield is attached to the crown guard that completely covers the blade at all times.

Sarge..

[Bob Slater]

I am thinking of making a riving knife for my old General 250 table saw. Should it be the exact same thickness as the teeth of the blade, or different?

[Daniel Hillmer]

I am thinking of making a riving knife for my old General 250 table saw. Should it be the exact same thickness as the teeth of the blade, or different?


Ask this guy first:

http://shop.walnutacrewoodworking.com/main.sc

He might already have one.

[Anthony Whitesell]

The one thing that everyone missed is that riving knives are usually attached to the trunion such that they tilt with the blade. Most splitter only work at 90 degrees and must be removed for most bevel cuts.

[Jim Becker]

The one thing that everyone missed is that riving knives are usually attached to the trunion such that they tilt with the blade. Most splitter only work at 90 degrees and must be removed for most bevel cuts.

I've never encountered a splitter that did not tilt with a bevel. That's not generally a differentiator between a "traditional" splitter and a riving knife. The splitter, however, does not go up and down with the arbor when you adjust cut height...the riving knife does, meaning it will always have exactly the same relationship to the blade physically no matter what the cut height is adjusted to.

[Jason Beam]

The one thing that everyone missed is that riving knives are usually attached to the trunion such that they tilt with the blade. Most splitter only work at 90 degrees and must be removed for most bevel cuts.

I think that's the other way around. They don't generally raise/lower with teh blade, but most actually DO tilt with the blade. Your situation seems to be the exception. :)

[Charlie Plesums]

My riving knife is very close to the thickness of the blade, as well as being very close to the blade. Therefore if you have a squirrely piece of wood that wants to touch the back of the blade and see if it can fly, the riving knife keeps it from getting much traction on those back teeth.

My previous saw had a splitter that was so inconvenient that it spent more time on the shelf than on the saw, and was such thin metal that wood could still get a good grip on those back teeth.

[Daniel Hillmer]

My riving knife is very close to the thickness of the blade, as well as being very close to the blade. Therefore if you have a squirrely piece of wood that wants to touch the back of the blade and see if it can fly, the riving knife keeps it from getting much traction on those back teeth.

My previous saw had a splitter that was so inconvenient that it spent more time on the shelf than on the saw, and was such thin metal that wood could still get a good grip on those back teeth.


What saw do you have?

[John Thompson]

I am thinking of making a riving knife for my old General 250 table saw. Should it be the exact same thickness as the teeth of the blade, or different?

No... it should be a few .000 under the width of the teeth, Bob. If you make it the exact thickness you would be inviting trouble.

An ideal riving knife would be slightly wider than the blade blank (body) and slightly narrower than the teeth kerf (and keep in mind that on ATB one is angled right and one is angled left. That width is generally stated as .126 for full kerf and smaller for thin kerf. That width will vary from one blade maker to another.

So again.. thicker than the plate but thinner than the kerf.

Good luck...

Sarge..

[Anthony Whitesell]

Granted I don't have a splitter (or riving knife or guard on saw). I don't see how this tilts with the blade. http://www.woodcraft.com/family.aspx?familyid=5067

[Anthony Whitesell]

Actually, I don't have a situation, yet, because my saw was made before splitters and riving knives and the guard was an option when it was made.

I've been looking and trying to decide what aftermarket safety features I should persue and which ones will fit on my saw.

[Art Mulder]

Granted I don't have a splitter (or riving knife or guard on saw). I don't see how this tilts with the blade. http://www.woodcraft.com/family.aspx?familyid=5067


That one, doesn't. Most splitters, though are attached to a mechanism behind the arbor inside the saw. The micro-jig splitter is rather unique in that it attaches to the zero-clearance-insert.

[Jim Becker]

What saw do you have?

Charlie uses a MiniMax combo machine and his riving knife setup is pretty much the same as on my MiniMax slider. I actually have two riving knives; one setup and on the machine pretty much all the time that was "adjusted" in height to allow it to work with non-through cuts with a 10" blade. (The machine is designed for 12" blades) and the original one that I use when I clamp on the dust hood/guard for overhead dust collection. As Charlie indicates, the riving knife on our machines is nearly the same thickness as our "standard kerf" blades and fits very closely to the contour of the blade. I never am uncomfortable when ripping very thin strips, for example...they just can't bend in behind the blade.

[John Thompson]

What saw do you have that was made before splitters and riving knives were in use? About all U.S. saws are clones of the Uni-saw that was introduced in 1937 which had a splitter. Since then I have never seen a TS without the capacity for a splitter. Even contractor saws I had back in the early 70's had splitters.

What I highly suspect (?) is your TS does have the capacity for a splitter and probably had one at one time? Someone probably didn't use it which is more than common and it didn't go with the saw on a re-sale as it was either lost or thrown away. I threw a few splitter guards away myself back in the 70's and early 80's.

Sarge..

[Charlie Plesums]

What saw do you have?


Charlie uses a MiniMax combo machine and his riving knife setup is pretty much the same as on my MiniMax slider....As Charlie indicates, the riving knife on our machines is nearly the same thickness as our "standard kerf" blades and fits very closely to the contour of the blade. I never am uncomfortable when ripping very thin strips, for example...they just can't bend in behind the blade.

Jim beat me to the answer, and said it very well. It was a big investment, but not as big as the van I bought to support my woodworking. When I wanted to visit one before I bought, MiniMax said that no "garage woodworker" gets a machine like I have, but there are now 3 of them in Austin alone, not counting it's little brother (with the merely 12 inch jointer).

[Anthony Whitesell]

Craftsman 103.20000. The guard support (ie., splitter) and guard was an option. The motor was sold separately, so the saw cost only $87 new, or $123.50 with a 3/4HP motor, $131.50 with a 1HP motor. The guard/splitter were $5.35 and sold separately. I purchased the saw used and he had bought extra side extension tables for the saw but never bought the guard. Ahh...the good old days.

I thinking of an overhead guard and a riving knife. Any one know if the make a riving knife for 8 1/2" and 9" table saw blades?

[Rod Sheridan]

I am thinking of making a riving knife for my old General 250 table saw. Should it be the exact same thickness as the teeth of the blade, or different?

Hi Bob, the spec's for riving knives in Europe state that the knife has to be thicker than the saw plate (body) and thinner than the kerf width.

If you change from a standard to a thin kerf blade, you install the matching riving knife.

Regards, Rod.

[Chris Padilla]

Switch to a bandsaw...no worry about kickback...no need for a riving knife or splitter!

;)