Torque Specs and lubricating the bolts?

Just curious if anyone has heard of this or can confirm or deny the below information? I don't know if I would reccomend oiling bolts before torquing them but I have torqued many a nut & bolt that was still greasy, grimy and or gunked up... not to mention, how would anti-seize or thread lock affect the torque specs? the below is from an article that i read at:

what do you think???

I was being very careful with my new bike. I was using a torque wrench on all the bolts. When I was putting it all back together I thought that I would clean and oil the bolts that bolt the cam retainers to the head. I put the cams back, placed the cam retainers back on and started to torque the cam retainer bolts back to the correct torque listed in the shop manual then , I broke one of the grade 12.9 hardened steel bolts off in the soft aluminum cylinder head. The realization of what I had done hit me like a 2x4. I shouldn't have oiled the bolts. Oiling the cam retainer bolts allowed them to turn further with less torque, over-tensioning them. After calming down for a couple of days, I removed the cylinder head and had the partial bolt removed by wire electro-discharge machining. I then had the threads helicoiled back to the original size. I've got over 10,000 miles on my KLR650 now.

Maybe he actually poured oil into the threaded hole and created a hydraulic failure???

Bueller? anyone?


a.k.a. MainLine

a.k.a. SuaveGato

Depends on what you're working on. If you're working on something with stainless steel nuts and bolts and Don't lubricate the threads you may not be able to get them apart because the threads can gall and sieze together. Torque specs are generally given for dry threads which I have always had a problem with. You are supposed to reduce the torque spec by a certain amount that I can't recall if you oil the threads. For that guy to have snapped the bolt off just because of oiling the threads sounds suspicious. Maybe he used foot lbs instead of inch lbs :naughty: In some applications they measure the stretch/ length change of the bolt when torquing, in which case lubrication wouldn't matter. NASCAR engine builders and NASA engineers please reply. :naughty:

I agree. All other things being the same, oiling the bolts is not going to snap one off. I would have thought that this would b a good practice as torgue measurements are probably more accurate. I would do it if I was more organized and could remember.

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