Do you use anti-seize on spark plugs?
#112
That being said, if the factory service manual specifically states to put antiseize on and torque, their torque spec is for lubricated threads, so it isn't an issue.
Last edited by d_slat; 10-07-2018 at 06:59 AM.
The following 2 users liked this post by d_slat:
greggreen (10-07-2018),
JayStronghawk (10-10-2018)
#113
Antiseize will not cause "overtorqe" BUT IT WILL CAUSE OVERTIGHT! If you put antiseize on threads it reduces friction. If you tighten to the same torque recommended for dry threads, they will be overtightened. Often times it doesn't hurt anything, but I've seen fasteners broken and threads pulled out due to this.
That being said, if the factory service manual specifically states to put antiseize on and torque, their torque spec is for lubricated threads, so it isn't an issue.
That being said, if the factory service manual specifically states to put antiseize on and torque, their torque spec is for lubricated threads, so it isn't an issue.
#114
Torque is an indirect indication of the tension in the fastener. If you artificially reduce the friction, the tension in the fastener will be higher to compensate. If you don't believe it, try it. See how much torque it takes to snap a fastener dry, then repeat the test with anti-sieze on the threads.
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greggreen (10-08-2018)
#115
Just the first decent chart I found displaying the phenomenon John is describing. It's well documented. Look it up for yourself.
Clamping force at a given torque with different lubricants applied to threads and under the fastener head...
https://www.arielcorp.com/Support/Tech-Tips/ATT-14-02/
Clamping force at a given torque with different lubricants applied to threads and under the fastener head...
https://www.arielcorp.com/Support/Tech-Tips/ATT-14-02/
Last edited by cggorman; 10-07-2018 at 01:46 PM.
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John CC (10-07-2018)
#116
Exactly! If you look a the chart above, you see that for this particular fastener and torque, dry zinc plated threads nets you about 12,500 psi in the fastener, whereas copper anti-seize nets you close to 27,500 psi, more than twice as much!
Finger tight plus 1/4 turn (or whatever) gets you the same tension regardless of the conditions.
Finger tight plus 1/4 turn (or whatever) gets you the same tension regardless of the conditions.
#117
Exactly! If you look a the chart above, you see that for this particular fastener and torque, dry zinc plated threads nets you about 12,500 psi in the fastener, whereas copper anti-seize nets you close to 27,500 psi, more than twice as much!
Finger tight plus 1/4 turn (or whatever) gets you the same tension regardless of the conditions.
Finger tight plus 1/4 turn (or whatever) gets you the same tension regardless of the conditions.
The following users liked this post:
John CC (10-07-2018)
#118
#119
I always use anti seize on sparkplugs. Used to crew chief a Porsche in TransAm, learned to use it way back then. You can usually get a little fast food ketchup packet size anti seize packet at the auto parts stores for a buck. I have a 6 or 8 ounce container of the stuff which is a lifetime supply. I have used it to assemble tight fitting exhausts and it definitely makes slipping them on easier. I also use it when I attach a brake caliper because its a steel bolt threaded into an alloy caliper. You can cut corners when you are wrenching and get away with it but you strip the plug threads out of a head and you will be one unhappy camper.
#120