# Stuck Arbor Nut



## wcunnin3 (Jun 25, 2012)

So, I bought a used Unisaw that came with a Diablo 80t blade, which was nice, except that I cannot for the life of me loosen the arbor nut to change blades. The guy that owned it previously did a lot of mechanical work, and I think he may have overtorqued it when putting it on.

It's a right-tilt saw, so the threads are left hand. I managed to rig up a way to hold the blade still, but turning the wrench with considerable force turns the nut and the arbor (I guess spinning it within the bearing?). Do I need to try an impact wrench? What about using penetrating oil?

Any thoughts?

Thanks,
Will


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## MonteCristo (May 29, 2012)

My Unisaw has opposing flat spots on the arbor shaft for a second wrench. Your saw most likely does too. It sounds like it is LH thread but that should be clear just by looking ciosely at the end of the arbor shaft.

When you spun the whole deal, all that was doing was making everything (motor, belts etc) except the blade turn. No big deal.

BTW, using the blade that way is frowned on as there is the possibility of blade damage . . .

Putting a little penetrating oil on the nut/shaft is likely a good idea too, especially if it looks rusty.

Finally, overtorquing this nut is a poor idea. The big arbor washers are supposed to be compressed slightly, not flattened !

Good luck.


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## knotscott (Feb 27, 2009)

Be sure you pull towards the front of the saw to loosen it.


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## IrreverentJack (Aug 13, 2010)

*pull towards the front of the saw to loosen*

Right-tilt with left handed thread = pull towards front to loosen.
Left-tilt with right handed thread = pull towards front to loosen.

I had to stare at my saw a while before I wrote that. Thanks Scott. -Jack


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## Dusty56 (Apr 20, 2008)

I was also going to ask about the wrench flats on the inside of the blade arbor.


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## MonteCristo (May 29, 2012)

I like knotscott's tip ! Takes the clockwise vs counterclockwise thinking out of it . . .


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## lumberjoe (Mar 30, 2012)

You are using two wrenches, right? You need to lock the arbor to loosen the nut. I am not familair with Unisaws, but every table saw I have changed a blade on required two wrenches; one on each side of the blade. One loosens the nut, one keeps the arbor from spinning. My miter saw and circular saw have arbor lock buttons.


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## wcunnin3 (Jun 25, 2012)

I didn't see any flats for a second wrench. The Unisaw manual from around the time of my saw actually instructs you to stick a piece of wood under the blade to hold it while you turn the nut towards the front of the saw, which is what I initially tried.

This is the arbor and arbor nut:









And this is the backside (don't see anywhere for there to even be any flats):









That sucker is on there tight, though. I can't get back to it until this weekend. I am going to get some impact sockets and try to take it off that way, though I am hesitant, lest I make the situation worse.


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## helluvawreck (Jul 21, 2010)

If all else fails you can always split the nut in a couple of places with a small grinder. go almost to the threads but not close enough to touch or damage them. It will probable come off with a wrench after that but if it doesn't you can then put a cold chisel in the groove and tap it a little but don't hit hard. If it still won't budge soak it a little more and try again. We've gotten a lot of nuts off of old machinery this way at the plant. Hopefully your threads are ok.

helluvawreck
https://woodworkingexpo.wordpress.com


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## MonteCristo (May 29, 2012)

Must be a pretty old saw. Any idea of its vintage ?

Another idea would be to somehow jam the drive pulley and belt(s) so that you don't turn the whole deal when the blade slips. Maybe attach a clamp that swings up and jams against the frame when you turn the nut ? Things don't look rusty so it must just be tight. As helluvawreck says, if all else fails . . .


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## Enoelf (Mar 15, 2012)

It is a reverse thread, so it is clockwise to loosen, just keep that in mind before you hit it with an impact wrench. I have seen some saws (not necessarily a unisaw) that have a detent that locks the spindle shaft in place.
Splitting the nut isn't a bad idea, but before I tried that, I would try to secure the backside of that arbor with a hefty pair of vice-grips, and remember that the nut needs to turn clockwise to loosen.


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## teejk (Jan 19, 2011)

think Delta has a "fixed" big flange on the "non-nut" side. that should have 2 flat sides behind it that accept an open end wrench (the Delta stock wrench is actually just a piece of heavy gauge steel with a slight bend in it). It looks like you have that but it was painted (perhaps lipstick on the pig?).

your arbor nut looks pretty rough (as does the outer flange). but before I did "impact", I'd go liguid wrench followed by a propane/MAAP torch if needed (the combination can be pretty effective).

the nut should heat up pretty fast (expand) and give you a chance. and I think most saws violate the "tighty/righty" rule…designed so rotation (top of the blade always coming toward you) will not spin the nut free, only tend to tighten it.


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## wcunnin3 (Jun 25, 2012)

I think it's from 1966 but have not been able to verify that other than checking on vintagemachinery.org.

I've definitely been trying to turn the nut clockwise but with a constant force from me and a wrench instead of the taps of an impact wrench.

Funny though, I had to get a regular bolt out of junk box and hold it up next to the arbor to see the opposite threads and make sure I wasn't crazy.


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## dlmckirdy (Oct 27, 2009)

After soaking some penetrating oil on the threads, try TIGHTENING it even the very slightest amount of movement. Sometimes you can break the friction lock on the threads this way with less torque than loosening. Use the oil on the nut/threads, and nut/washer interface only. Do not oil the washer/blade interface - you will want that friction surface with the new blade!


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## wcunnin3 (Jun 25, 2012)

I'll definitely check behind the flange. I spun the arbor last night and looked at the fixed flange but saw no flats. I don't think there would be any room to get a wrench in there if the flats are behind the flange; maybe the reason for the "bent" wrench.

I appreciate all of the input, as I really want to get this nut off so that I can get my new combination blade on, get everything ali


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## dbhost (Jul 20, 2009)

There has to be some way to lock the arbor. Either a push button mechanism, or a couple of flats on the inside of the arbor for an arbor wrench. Because if there wasn't some way to hold the arbor still, the nut wrench would just spin the arbor…


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## wcunnin3 (Jun 25, 2012)

I downloaded a copy of the manual from the mid-60's, and it literally instructs you to place a block of wood under the blade to hold it steady. I will search for the flats, though, in hope that there is an easier way.


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## Oldelm (Jun 11, 2012)

Try this. Get some piece of heavy steel, a hammer head or the like and hold it on the under side of the nut. Take a cold chisel with a sharp but wide grind. Place the chisel across the nut an give it a sharp rap with a fairly heavy hammer. This springs the nut and expands it somewhat. It should remove in the normal wood block method. I would stay away from heating until last resort. Overheating does some odd things to metals. Replace the arbor nut after doing this procedure it won't be reliable after it is sprung with the chisel. It probably is not good now, pulled threads more then likely. This is not my trick. I have seen it done many times and have done it myself on all kinds of machinery.


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## dlmckirdy (Oct 27, 2009)

With the Unisaw, you can remove the table and get considerably more working room to use any of the methods listed above. The trunion is mounted to the cabinet frame, not the table as with the cheaper "bench" saws.


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## donwilwol (May 16, 2011)

If all else fails, squeeze the belt together in front of the pulley ( as close as practical) and either duct tape the crap out of it or wrap it with good strong twine. That should prevent the shaft from turning. I'd then use the impact wrench.


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## DS (Oct 10, 2011)

A little heat will expand the nut some and get things moving. 
Just be sure to wear your oven mits.

I used Unisaws since the early 80's and the wood block to the blade was the preferred method to secure the arbor whilst loosening the nut. 
I'm not saying that it's the best way, but, for that saw, it seemed the only way. (If memory serves)


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## Alexandre (May 26, 2012)

Put some wd40 on it, the get a wrench and a pipe, as the price is a longer lever and make it easier.


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## teejk (Jan 19, 2011)

given the estimated age, I guess Delta added the "flats" later. The wood block wedge is what I use on my vintage Cub Cadet mower blades but there I can use an air impact wrench like your tire guy uses.

I can't picture any tool that can grip the arbor in that tight space but if you can wedge the blade with a scrap of wood, hit it with pen oil and get at the nut from below with impact, give it a shot.

as for heat, in combination with the penetrating oil I've had pretty good luck (and at times give it another squirt while hot…hold your breath though…it gives off some nasty stuff!).

I agree with the above about excessive heat…don't ruin the arbor. but the metal mass on the nut isn't much and a touch of heat should allow it to expand (at which time it might accept more penetrating oil…will help if your problem is junk on the threads as opposed to a mechanical issue caused by over tightening).

I'll shut-up now and let you concentrate on comments posted by people that have been there done that.


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## lieutenantdan (Feb 1, 2012)

Pardon my stupidity if I am wrong, but isn't that saw blade on backwards??


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## wcunnin3 (Jun 25, 2012)

Lt. Dan, it just appears that way from the angle of the photo. It's a right-tilt saw, so the arbor nut is on the left (if looking from the front of the saw). The 80t blade makes it hard to see where the points are facing.


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## lieutenantdan (Feb 1, 2012)

Oh. A Republication saw (right tilt).


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## Kentuk55 (Sep 21, 2010)

You have me very confussed. Stand at the table like you would to cut a board, and take a pic of the blade. The pics you took look like the blade is on backwords to me…. Either I am old fashion, or just plain old. I've never seen an arbor lock on a table saw… I've never seen that you had to use 2 wrenches to tighten a blade….......... You only need to "snug" it tight, that's it. I use a piece of scrap to hold the blade and put a wrench on it to "snug" it…that's it Take it off the reverse way. I don't damage my blade or anything else. Jus sayin.. Good luck with it for sure. If ya have too, clamp the blade with a pair o vise grips as long as you can get past the teeth. Sandwich the blade in 2 blocks of wood with sandpaper on them to help hold the blade, and see if you can get it to budge…. Maybe you're just tryin to turn it the wrong direction.


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## Howie (May 25, 2010)

Roger, my new General has an arbor lock. My old Ridgid 3650 needs two wrenches. You are correct when you say snug is tight enough.


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## Kentuk55 (Sep 21, 2010)

Thnx Howie. I know, I'm out in left without a glove sometime… hehe but, snug is where it's at..  I hope the other owner didn't put any lock tite on there..


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## whitewulf (May 11, 2010)

I recommend Kroil, it is sold every where that sells cleaning supplies for firearms. It ie better than the old Liquid Wrench before OSHA labeled as carcinogen! Beats WD-40 and such.


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## craftsman on the lake (Dec 27, 2008)

An impact wrench will loosen the nut without having to immobilize the blade that much.

One thing that almost always works on tight nuts is heat. A short while with a plumbing hand torch would do it. Watch out for any sawdust though. Don't want to burn your shop down. Watch out that you don't heat your bearings though. The shaft is big so it can absorb a fair amount of heat.


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## upinflames (Jun 24, 2012)

If I'm not mistaken, the nut is coupled with a 2 1/2" stabilizer washer, hence the problem, the paint on the saw blade is what has "glued" all this together, if your going to chunk the blade, just heat the blade around the washer and it might give it up.


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## lumberjoe (Mar 30, 2012)

I've done (and do) a ton of automotive stuff. It's safe to assume every single bolt on a car (except the oil drain plug, it's soaked in oil) is NOT coming off. WD-40 is not a penetrating oil. Technically it may be, but it's terrible for that purpose. I use it to push water out of electrical connections or where water shouldn't be.

PB Blaster is where it's at. That is the only penetrating oil I will ever use.

Roger, I have never used a table saw that wasn't made this century. I had no idea there was no flat spots on the other side of the arbor. That just doesn't make sense!

I would PB blaster it, let it sit. lock the blade in place however you can (maybe clamp a board to the table and set the teeth in it), and tighten the bolt a bit. This should free it. Once you get movement, loosen it up.

I'm not sure what kind of impact gun you have, but I'd be a little hesitant to use it. I have an IR titanium with around 1200lbs of torque. I've done some serious damage with it on stuck nuts. Either the nut explodes (that's ok), the stud pulls out (not good) and I've actually twisted/broken studs. There is torque control for forward, not reverse. On my saw, I would actually have to use the gun in forward (righty loosen) but I am not sure about yours being right tilt.

Edit - If the nut is on there THAT tight, locking down the blade may not help. You'll likely be able to spin the blade on the arbor.

One other suggestion is to get another arbor nut or even two. Lock them together at the end of the arbor. Put a huge pair of vice grips on the nuts and put something in place to prevent the vice grips from spinning. Contact with the table may be enough. Grab an opened end wrench and put it on the stuck arbor nut after spraying it down and go to town. If it still won't budge, throw a long pipe on the end of it for some leverage.


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## PurpLev (May 30, 2008)

penetrating oil /or/ heat and use light hammering on the wrench with the blade locked with a block of wood (old saws did not have a locking mechanism for the arbor - they recommended using a block of wood to keep the blade in place "locking the arbor" that way)


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## ajosephg (Aug 25, 2008)

Gentlemen: Quit talking about locking the blade. The OP said the arbor spins on the blade.


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## killerb (Nov 1, 2011)

I have a 1941 unisaw. The older ones did not have flats. Use the wood to hold agaist the blade and the wrench to loosen the nut. Just like the book says. Please don't go cutting the nut off or beating it off. It is a very simple process. Yes the blade in the picture is on the correct way. The dust shroud is in the front of the sawblade. Just where it should be. Good luck. bob


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## lumberjoe (Mar 30, 2012)

Thus my ninja edit (that my get missed). I'm pretty sure this will work:

Edit - If the nut is on there THAT tight, locking down the blade may not help. You'll likely be able to spin the blade on the arbor.

One other suggestion is to get another arbor nut or even two. Lock them together at the end of the arbor. Put a huge pair of vice grips on the nuts and put something in place to prevent the vice grips from spinning. Contact with the table may be enough. Grab an opened end wrench and put it on the stuck arbor nut after spraying it down and go to town. If it still won't budge, throw a long pipe on the end of it for some leverage.


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## IrreverentJack (Aug 13, 2010)

Clamp the pulley. Use a long box-end wrench. Tap/wack it with a hammer. Use an impact wrench if you have it. I would use heat or cold only as a last resort. -Jack


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## whitewulf (May 11, 2010)

Penetrating oil will work, soak it best you can. Use a brass drift of brass hammer, tapping lightly will set up vibrations & allow the oil/fluid to do its job. Patience not brute force, or you will bend the arbor or gall the threads.


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## Dusty56 (Apr 20, 2008)

If it's not rusted on , there's nothing to penetrate.
A friend of mine had the same issue a few years back. 
We were able to grip the arbor side flange with a LARGE pair of Channellock pliers while the nut was turned free.
Make sure you have the pliers facing the correct way for maximum gripping power , otherwise they will just slip around the flange.


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## lieutenantdan (Feb 1, 2012)

Dynamite. Works every time.


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## whitewulf (May 11, 2010)

Have you got that sucker off yet?


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## gfadvm (Jan 13, 2011)

I agree with whitewulf- we need an update.


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## Howie (May 25, 2010)

Me too


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## cutmantom (Feb 2, 2010)

i would try taking it off like you started to but hold pressure on the wrench with one hand and tap the end of it with a hammer, you can try this in both directions to possibly shake it loose


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## bobsmyuncle (Jan 12, 2011)

re: penetrating oil

"The April/May 2007 edition of Machinist's Workshop did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better.

Penetrating oil . Average load .. Price per fluid ounce
None ….............. 516 pounds .
WD-40 …........... 238 pounds .. $0.25
PB Blaster …...... 214 pounds .. $0.35
Liquid Wrench … 127 pounds .. $0.21
Kano Kroil …..... 106 pounds .. $0.75
ATF-Acetone mix.. 53 pounds .. $0.10

The ATF-Acetone mix was a 50/50 mix (1 to 1 ratio)."


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## teejk (Jan 19, 2011)

waiting for the results (and not just for him…whatever happens will be good to know beyond table saws).

this is like pacing in the maternity ward!!!


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## 280305 (Sep 28, 2008)

this is like pacing in the maternity ward!!!

That made me laugh out loud! Perhaps someone from the medical profession will speak up here, but I am pretty sure that the normal birthing process does not involve the use of penetrating oils, chisels, hammers and impact wrenches.


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## lieutenantdan (Feb 1, 2012)

I am beginning to think my recent sinoplasty was easier than this. Yes, they used a chisel.


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## wcunnin3 (Jun 25, 2012)

SUCCESS!!

Sorry for taking so long to reply, but I was out of town for work and then did not have a chance to relay the good news. No, there were no flats on my arbor and no button to hold it still. Yes, I used a block of wood against the saw blade (which was pointing the right way).

Lacking any pen. oil at the time, I used some Ed's Red that I had in the garage for my guns. A healthy dose of that, an overnight wait, and then some contorted use of a cordless impact driver finally got it off. Thank God I didn't have to take the table off … sucker weighs a ton.

I appreciate all of the input, as I was about flustered trying to wrench that sucker off. Just in case anyone was wondering, I put it back on wrench tight but not with any power tools or breaker bars.

Now on to build a cross-cut sled!


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## teejk (Jan 19, 2011)

ChuckV…maybe you are onto something…anything to speed the process LOL


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## knotscott (Feb 27, 2009)

Yippee!!!


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## teejk (Jan 19, 2011)

will

check the outer flange for flat.

and "wrench tight" is maybe too much…"wrench snug" is all you need…let's not repeat!

but congrats!


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## whitewulf (May 11, 2010)

Close, but no cigar, I think EDSRED is repackaged Kroil.LOL (Compettion shooters have been using Kroil for many years!) The impact wrench provided the vibes to allow oil to work!

Bobsmyuncle, I was very close in my suggestion. But I will check out acetone mix. The ATF will make it red Too!


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