Tip: Reduce Torque When Using Antiseize

[TxGreaseMonkey]

Antiseize compound is a lubricant. Accordingly, you need to reduce the torque on spark plugs and fasteners about 30%. This will help prevent stripping threads, particularly in aluminum block engines. Use antiseize sparingly. A "half a pea size" drop on spark plug threads is all that's needed. Allow thread rotation to spread the compound. High temperature nickel compound is the product of choice. It's harder and keeps dissimilar metals apart.

ASME torque convention is dry (without lubrication), unless specified otherwise. Pay attention to this when tightening head bolts and changing spark plugs.

 

[obbop]

Pocorn popping, hot chocolate brewing.... sitting back in anticipation of the coming show!!!!!

 

[Tosh]

I've set up my folding chair and picnic basket for a front row seat for this one....

 

[TxGreaseMonkey]

Helmet and kevlar vest are on and guns are loaded. Now, keep your head down and await the thunder of the incoming rounds.

 

[labman]

It only makes sense to reduce the torque if you use anti seize. I am a strong believer in using it where there is moisture or anything I screw into an aluminum housing. I always use a little on spark plugs and wheel studs.

So how much? I have seen several post saying 20%. Anybody have real data on this? What would be a simple test? Buy a dozen good say 8 mm bolts. Twist off 6 of them dry, and calculate the average, then the other 6 with anti seize?

 

[srivett]

Uh, I'm pretty sure my 1992 VW Golf was built with copper antisieze used on everything. Not using antisieze on part replacment would end up with a lot of loose fasteners. I guess there is the possibility that it has been completely dissassembled in the past but I doubt it.

If you have a factory manual for just about anything more complex than a rocking chair you'll see that it tells you where and where not to use antisieze. You'd be a fool to put it on your wheel studs and then undertorque them 30%! You aren't even supposed to use it there, period. If you have a Haynes, Chilton, etc. good luck.

I hope this is enough fuel to start the fire.

Cheers, Steve

 

[427Z06]

Maybe after TxGreaseMonkey gets some good feedback, like caveats on certain tips, he could put all his tips in one thread and have it stickied to the top of the Mechanical /Maintenance Problems, Tips, and Tricks topic thread.

 

[TxGreaseMonkey]

Usually figures given for U.S. equipment suppose dry assembly, unless stated otherwise. The proper thread stretch depends on whether the engineer calculates the required torque assuming dry or lubricated threads. The table below gives generic torque values for dry and lubricated threads. The point was made to check first. You need to find out for sure, because lubing the threads and bolt head will definitely result in generating a higher stress (thread stretch) on the bolt than what the torque wrench tells you that you are generating. Thread locking compounds, such as Loctite, have a lubricating effect, as well.

U.S. BOLT TORQUE SPECIFICATIONS

Torque in pounds-foot
2 2 5 5 7 7 8 8 Socket head cap screw Socket head cap screw
Bolt Dia. Thread per inch Dry Oiled Dry Oiled Dry Oiled Dry Oiled Dry Oiled
1/4 20 4 3 8 6 10 8 12 9 14 11
1/4 28 6 4 10 7 12 9 14 10 16 13
5/16 18 9 7 17 13 21 16 25 18 29 23
5/16 24 12 9 19 14 24 18 29 20 33 26
3/8 16 16 12 30 23 40 30 45 35 49 39
3/8 24 22 16 35 25 45 35 50 40 54 44
7/16 14 24 17 50 35 60 45 70 55 76 61
7/16 20 34 26 55 40 70 50 80 60 85 68
1/2 13 38 31 75 55 95 70 110 80 113 90
1/2 20 52 42 90 65 100 80 120 90 126 100
9/16 12 52 42 110 80 135 100 150 110 163 130
9/16 18 71 57 120 90 150 110 170 130 181 144
5/8 11 98 78 150 110 140 140 220 170 230 184
5/8 18 115 93 180 130 210 160 240 180 255 204
3/4 10 157 121 260 200 320 240 380 280 400 320
3/4 16 180 133 300 220 360 280 420 320 440 350
7/8 9 210 160 430 320 520 400 600 460 640 510
7/8 14 230 177 470 360 580 440 660 500 700 560
1 8 320 240 640 480 800 600 900 680 980 780
1 12 350 265 710 530 860 666 990 740 1060 845


BOLT TORQUE FACTORS

LUBRICANT OR PLATING TORQUE CHANGES
Oil, Reduce torque 15% to 25%
Dry Film (Teflon or moly based), Reduce torque 50%
Dry Wax (Cetyl alcohol), Reduce torque 50%
Chrome plating, No change
Cadmium plating, Reduce torque 25%
Zinc plating, Reduce torque 15%

Baseline torque is calculated for a non-lubricated, unplated bolt.

For spark plugs, I would call the manufacturer and ask them what torque they recommend if you use antiseize. Stripping threads is one of the great sinking feelings in life. Act in haste, repent at leisure.

[ July 17, 2005, 08:37 AM: Message edited by: TxGreaseMonkey ]

 

[Bret Chase]

quote:

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Originally posted by srivett:
Not using antisieze on part replacment would end up with a lot of loose fasteners.

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anti-seize isn't loctite.. it isn't going to prevent parts from loosening up, if anything it will facilitate it

quote:

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You'd be a fool to put it on your wheel studs and then undertorque them 30%!

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Now I don't use anything on my wheel studs, but using a lower torque value w/ lubricated studs will result in a similar clamping load. It can even be argued that it gives a more even clamp load, by reducing the torque required to get the lug nuts moving. (of course setting clamp load by torque is a lousy way to do it... CL can vary up to 40%.. turn of nut is far more precise but rarely used in autos (with the exception of most head bolts/studs)

that being said.. I really HATE it when ppl lubricate their wheel studs then pound on the nuts with an impact wrench. I was working on my parent's van a while back, and the morons who worked on it last did exactly that... My Chicago Pneumatic impact wouldn't even touch the nuts.. it took my 2ft breaker and a 4' pipe to break them loose. first thing I did was remove all the AS goop from the studs.

 

[acranox]

There is a little book called the "Pocket Ref"
You can get it on Amazon

It outlines several different lubricants and how to adjust torque accordingly. These numbers are also in my textbook for my automotive class.
If anyone wants, I'll post pictures of the pages from the books.

 

[labman]

quote:

---

Originally posted by acranox:
There is a little book called the "Pocket Ref"
You can get it on Amazon

It outlines several different lubricants and how to adjust torque accordingly. These numbers are also in my textbook for my automotive class.
If anyone wants, I'll post pictures of the pages from the books.

---

Yeah, much better than the crude test I suggested.

 

[TheLoneRanger]

quote:

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If anyone wants, I'll post pictures of the pages from the books.

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Acranox, I for one would be interested in the numbers for the most common lubes.

As a rule of thumb, I've always reduced torque by about 10% when using anti-seize. It would be interesting to see what the book says.......

 

[mechtech]

Torque values in manuals are given with either dry, or a specific wet condition, for the threads. This is usually stated, and is what the torque values are predicated upon.

 

[srivett]

Another thing is that they assume new fasteners or fasteners that have had their threads re-cut. If you take off a fastener and it heats up enough to burn you it's going to need some oil to get a good clamping force vs torque ratio when you put it back on.

I don't torque anything to spec unless it is critical anyway. The gut-feeling meter works pretty good unless you are working inside an engine. Any safety item will usually have a cotter pin or lock-nut.

Steve

 

[acranox]

Okay, here's what I've got
From my textbook (Automotive Technology 3rd edition by Jack Erjavec, Delmar publishing)
http://www.acranox.org/images/table13-2.jpg
http://www.acranox.org/images/table13-3.jpg

From the Pocket Reference (3rd edition, Thomas J. Glover, Sequoia publishing)
http://www.acranox.org/images/pocketref.jpg

The Pocket Ref is an AWESOME book, it is almost 800 pages of stuff. I rarely use it, but I love having it. To get a better idea of it's contents go to the Amazon link in my post above, and below the picture of the book cover click on "Look Inside This Book"

 

[1sttruck]

I like having a light coating of anti-sieze on the wheel studs, actually on a number of threads if I'm not using a thread locker. Even a thin coat wire brushed on makes a big difference down the road. I use winter tires on all three vehicles, and often end up changing my own as the shops are typically full when I want to change them. I haven't seen a 'loose' lug nut when changing the tires, but perhaps it's also because I use a torque wrench in an attempt to minimize tweaking the rotors. A couple of coworkers have complained that they couldn't change a flat tire, and even their husbands spent a fair amount of time trying to break loose rusty, frozen lug nuts, in cold rain on a busy road.

The torque specs for the sedans have something like a +/- 10 lb range for about +/- 10% of the spec, so just torquing on the lower half seems to work fine.

 

[Shannow]

I vastly prefer to work on strain than torque in everything.

 

[JMG]

I am going to install new plugs on a 01' CRV, how much torque should I put on the plugs? Manual says use anti-seize and torque 13ft-lbs.

 

[TxGreaseMonkey]

JMG, I'd torque them to 10 ft-lbs, if you use antiseize.

 

[labman]

quote:

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Originally posted by JMG:
I am going to install new plugs on a 01' CRV, how much torque should I put on the plugs? Manual says use anti-seize and torque 13ft-lbs.

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Use anti-seize and torque 13ft-lbs.