# Ridgid R4512 thin kerf riving knife?



## mprzybylski (Nov 21, 2011)

I've been considering lately the use of TK blades in my 4512 as I'm starting to think some of the operations I've been doing with hardwood lately have caused it to bog down a bit with my normal blades. The one thing I can't seem to find is a TK riving knife for this saw. I did find one that costs $32 shipped but was wondering what everyone else with this saw does when using TK blades?


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## knotscott (Feb 27, 2009)

AFAIK, the riving knife (RK) on your R4512 is no thicker than most 3/32" TK blades (most range between 0.091 0.100", and IIRC the R43512's RK is 0.09")...add a small amount to the blade's total kerf width for arbor, flange, and blade runout, and there should be no problems passing the RK unless you use an ultra thin kerf blade.

I'd stick with good blades….there are premium blades from Infinity, Forrest, Ridge Carbide, Tenryu's Gold Medal line, CMT's Orange, Freud's Premier/Industrial, and Amana Tools. There are good value lines from Freud's Diablo, Irwin Marples, CMT ITK Plus, Oshlun, Amana AGE, Tenryu's Rapid Cut series, and DeWalt's Precision Trim, among others. I'd avoid Skil, B&D, HF, Vermont American, Avanti/Avanti Pro, Ryobi, Workforce, Irwin Marathon or Classic. Oldham Contractor series, and DeWalt's Construction series, as well as many other off names.


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## mprzybylski (Nov 21, 2011)

You're right Scott, I just measured it with a dial caliper and it read roughly .09 (I should have done this before posting, apologies). Turns out the crosscut blade I use (Irwin marples 80T) is also a bit larger like you said at roughly .098 (so its already TK) but that's not the blade I was referencing with my bogging down. I'm currently using the Freud heavy duty 24T ripper which is full kerf and I think I should switch over to the Freud TK LU87 instead for that. I also have the FK version of the woodworker 2 which doesn't see as much use anymore because I've begun to be a specialty blade switcher type of guy  I think my biggest gripe will be solved by switching to the TK ripper. Do you agree this would be a better ripper for my saw?


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## knotscott (Feb 27, 2009)

On a percentage basis, the full kerf LM72 is ~ 33% wider than the TK LU87…your saw should definitely labor less with the TK, and cut quality shouldn't suffer noticeably.


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## nwbusa (Feb 21, 2012)

Thin kerf blades will make a difference on the 4512, and the stock riving knife will work with most of them (it's a close fit so make sure the riving knife is well aligned-it's easy to adjust).


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## cutworm (Oct 2, 2010)

Makes a difference for sure. I bought a CMT that Knot mentioned. Liked it so much I ran back and bought a spare. I have the predecessor to your saw and they are pretty much the same. I did hit the leading edges of the knife with a file adding a little bevel to it. The saw even sounds different with one of those blades.


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## runswithscissors (Nov 8, 2012)

On another thread I suggested cutting up an old saw blade for a riving knife. And I did this, but it was a bit too thin. Then I ran into a suggestion to use 14 gauge plate steel. I dropped by my local steel supplier, and picked up an offcut about a foot square (enough to make 4 or 5 riving knives). With a little sanding and polishing, it works perfectly with my Freud Diablo TK blade. For a standard blade, you'd probably want 13 or 12 gauge. The way I checked it out at the steel yard was to bring a piece of oak from home in which I'd sawed a 6" kerf. Slipped nicely over the 14 gauge, with no wiggling, so I knew it was good.


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