An Aftermarket Retrofit Riving Knife Does Exist...

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Review by knotscott posted 06-09-2010 10:01 PM 67705 views 4 times favorited 27 comments Add to Favorites Watch
An Aftermarket Retrofit Riving Knife Does Exist... No-picture-s No-picture-s Click the pictures to enlarge them

The Bolt On Ripping Knife (BORK) from Bob Ross of Walnutacre Woodworking is a retrofit riving knife that fits several traditional saws that were not originally designed for a riving knife. The BORK attaches to the arbor swing arm, and rises, lowers, and tilts in unison with the blade much like a true stock riving knife does. I’ve had a BORK on my Shop Fox W1677 since August of 2008, and have been very happy with it. It’s available in full kerf or thin kerf thicknesses, and will currently fit Grizzly, Shop Fox, Delta Unisaws, and Jet JTAS cabinet saws, as well as Craftsman, Steel City and some Jet Hybrid saws.

Because the BORK is made to adapt to existing saws, there are challenges that Mr. Ross needed to address. As such, it’s not necessarily as elegant of a design as true riving knives that are fitted to saws that were designed from the ground up to accommodate the riving knife, but it’s a clever and effective design that offers the benefit of a riving knife to several older style saws.

Installation is moderately easy, and once adjusted properly, the BORK works quite well, basically mimicking the movement of the blade up, down, and when tilted. Note that because the BORK is attached to the end of a swing arm that extends beyond the arbor shaft, the BORK doesn’t necessarily rise and fall in direct proportion to the movement of the blade, though it’s close. As the blade is raised, the BORK travels a slightly greater distance up, and likewise when the blade is lowered, so the height of the BORK will not always be at the exact same height relative to the blade, though it can be depending on where you manually set the blade height initially. This is rarely a problem, and is most easily resolved by setting the BORK height the same as the blade height for common wood thicknesses, which puts the BORK at an ideal location for most boards. It can be easily manually adjusted up or down relative to the blade height to accommodate lower or higher blades heights as needed for exceptions. Also note that proper adjustment requires the use of a custom zero clearance insert to offer lateral support.

Bob Ross is an avid woodworker, very much like many of us, who evolved this device because it was said that it couldn’t be done. He’s also a super guy to deal with, and is honest and open about his invention. He offers discounts to forum members who will write a review of the BORK, and backs his invention with a 100% money back guarantee. It’s available for ~ $125 shipped at The BORK is a unique device unlike any other I’m aware of. It works well and I still get a kick out of watching the BORK rise through the throat insert on my saw.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

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27 comments so far

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#1 posted 06-09-2010 11:33 PM

super Review Scott your always on top of saws and accessories.well done.


View mrg's profile


870 posts in 3799 days

#2 posted 06-09-2010 11:44 PM


Looks like a great product. You must of purchased this when he first made them, I went to his website and the store link doesn’t work and the site has not been updated in a while except for the copy write date at the bottom.

Do you know if he still makes these? Maybe I was at the wrong site.

But none the less thanks for the review it looks like a good product.

-- mrg

View childress's profile


841 posts in 4342 days

#3 posted 06-10-2010 12:03 AM

The link is bad, found it at A little pricey for what it is. I guess you can do that if you have the only one of it’s kind

-- Childress Woodworks

View Routerisstillmyname's profile


763 posts in 4309 days

#4 posted 06-10-2010 12:08 AM

Thanks for the info. What a shame it doesn’t list the Ridgid Table saws, there must be few thousands out there.

-- Router è ancora il mio nome.

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8382 posts in 4175 days

#5 posted 06-10-2010 12:41 AM

Sorry for not including the BORK store link…I meant to and forgot. Thanks for posting it Childress.

Barry – I don’t know if it’ll fit any of the General’s or not. Bob could tell you, but those that I’ve seen have a cast blade shroud that would probably interfere with the motion of the riving knife. It’s possible that the BORK would fit the GI 50-250 and 50-260, which are Taiwanese imports that are more similar to the Griz and Jets, but again, Bob Ross could tell you with more certainty.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

View Dusty56's profile


11859 posts in 4488 days

#6 posted 06-10-2010 01:29 AM

Too pricey for my blood , but at least the shipping is included !
I’m going to have to stay with my splitter for now. Thanks for the review : )

-- I'm absolutely positive that I couldn't be more uncertain!

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812 posts in 4684 days

#7 posted 06-10-2010 03:53 AM

The price is nuts! He needs to sell his idea/patent to someone who can market and make much cheaper.


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200 posts in 4554 days

#8 posted 06-10-2010 04:35 AM

Good ole capitalism will bring the price down. Some others will design a bolt on riviing knife and it will be less than $125. I agree with Dusty. Splitter for now.

View Don Newton's profile

Don Newton

731 posts in 4418 days

#9 posted 06-10-2010 04:47 AM

$125 and you have to sign a waiver to boot! I’ll pass.

-- Don, Pittsburgh

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#10 posted 06-10-2010 04:49 AM

Thanks for the review.

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#11 posted 06-10-2010 06:53 AM

$125 and you have to sign a waiver to boot! I’ll pass.

/agrees with Don.

Thanks for the review.

-- Ohh mann...pancakes and boobies...I'll bet that's what Heaven is like! ♣ ♣ ♣ ♣

View knotscott's profile


8382 posts in 4175 days

#12 posted 06-10-2010 12:46 PM

I’m surprised at the number of comments about price. Stationary splitters like the Biese and Merlin range from $140-$200. This one moves with the blade and has a 100% money back guarantee, including shipping costs. Mass production would undoubtedly lower the price, but due to the potential liabilities, I believe Bob’s chosen to mainly offer these through woodworking forums, so the numbers are fairly small and are hand made.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

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#13 posted 06-10-2010 04:58 PM

Excellent review like always!

-- Please like and subscribe to my YouTube Channel

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#14 posted 06-11-2010 04:55 AM

i’ve been wanting to ask the question of how folks feel about the MJ Splitters ($15), are they as good as a riving knife? I am not crazy about the riving knife that came with my Hitachi table saw. looking for advice.

-- Chris

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2545 posts in 4757 days

#15 posted 06-11-2010 11:57 PM

Great review….
Biesmeyer makes a splitter that’s quick release, and bolts into the holes that my blade guard bolted into. Its designed for my Unisaw, and the reviews on it are good. It doesn’t move with the blade but its better than nothing. The only problem is that its $150.00! Overpriced, yes..but I will probubly buy one anyways…and

Barry…I love my Grrippperrr..I got the deluxe model…. it was on sale for around $50 and it blows away any “pushstick” I have ever used!


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