Aren't most/all of the fasteners plated though (black finish fasteners would show signs of rust very quickly) and for Japanese bikes I think cadmium finish is pretty common...in which case, according to the formula, there is very little difference in the equivalent torque for a greased thread (I'm presuming oil and regular grease have similar friction coefficients).
According to the quoted friction coefficients; Assuming cadmium plated fasteners then using grease/oil on the threads the torque should be between 94 - 112% of specified torque. For copper anti-seize compound use 75%. For zinc plated fasteners using grease/oil on the threads the torque should be between 75 - 90% of specified torque. For copper anti-seize compound use 60%. For black finish fasteners using grease/oil on the threads the torque should be between 50 - 60% of specified torque. For copper anti-seize compound use 40%. I'd be careful about greasing your nuts though (SA alert!!!) though as I would think some types such as those with graphite may have friction coefficients closer to anti-seize than regular oils. Joe. -----Original Message----- From: John Laurenson [mailto:[EMAIL PROTECTED]] Sent: Wednesday, July 03, 2002 8:52 AM To: [EMAIL PROTECTED] Subject: Re: dry vs. wet torque readings ??? Good information on the coefficient of friction, but I don't see how it addresses anything; other than if you use the copper anti-seize and the torque numbers in the manual are based on non-plated fasteners you have a problem. You will probably have the bolt fail in tension because you are apply nearly three times the tension load and the bolt will shear fail. The question still is "if the torque numbers in the manual are based on dry" is there a reduced torque number you need to use for lubricated because of the increased loading on the bolt? hawke On 7/3/02 10:38 AM, "Walt Garcen" <[EMAIL PROTECTED]> wrote: > The best torque wrench in the world doesn't know anything about coefficients > of friction or stress vs strain curves. Torque is torque and the issue here > isn't whether the tool is accurate within 10%, 1%, or 0.1%. > > -----Original Message----- > From: GTS-1000 Owners List [mailto:[EMAIL PROTECTED]]On Behalf > Of tom &jean > Sent: Wednesday, July 03, 2002 7:50 AM > To: [EMAIL PROTECTED] > Subject: Re: dry vs. wet torque readings ??? > > > Since I use the best torque wrench available ( made by the German mfg > Stahlwille) I do not have these > insignificant problems. > > Tom Beasley > > > ----- Original Message ----- > From: "Henry S. Winokur" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, July 02, 2002 10:31 PM > Subject: Re: dry vs. wet torque readings ??? > > >>> Since dry vs wet can vary greatly, any structural bolts that would be >>> torqued under my supervision must be done per the AISC Calibrated torque >>> wrench method to verify proper tension. But since you people are mere >>> peons, not able to fully appreciate a Wilhelm-Skidmore bolt tensioner, I >>> would go off the following rule of thumb torque formula: >>> >>> T=(KDW)/12=foot-pounds >>> >>> where T= torque >>> K=friction factor >>> D= Nominal bolt diameter in decimal inches >>> W=clamp load in pounds >>> K=0.30 for nonplated fasteners, black finish >>> K=0.20 for electrodeposited zinc coatings >>> K=0.15-0.18 for oils >>> K=0.16 for cadmium electrodeposited coatings >>> K=0.12 for copper anti-seize compound >>> >>> Standard practice is to tighten a bolt to 70-75% of the proof load. > Proof >>> load is the point where a bolt will permanently deform more than 2%. >>> >>> Let me know if you need any more schooling. >> >> What we need is ENGLISH not ENGINEERING-EZE. >> >> Regards, >> >> Henry S. Winokur >> 94 GTS1000, AMA, MRF, >> Nationally Certified Riding Instructor >> Columbia, MD Ride for Kids Task Force >> West Bethesda, MD USA >> > ====================================================================================== NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing, copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. ==============================================================================
