head bolt torque

Actually we are both right and both splitting hairs ....LOL
so on a total different note , since you obviously have a technical background you might find this interesting as its along the same idea. I used to own a cryogenic tempering service.This is/was cutting edge science of using liquid nitrogen to temper metal and non metalic items without the damage of heat(plus it goes to the core of the item). I had to set up a comparison to show the effectiveness of the process.Though its not scientifically correct and accuracy is suspect, it showed in a laymans fashion the effectiveness of the process.I had a 1 inch thick steel bar and a 5/16 steel bar matched and drilled for 1/4 bolts. We used plasti-gage to show the clamping force by laying it lengthwise down the 1 inch thick bar and clamping it down with the 5/16 plat. Using grade 8 bolts we torqued it to 40# then measured the plastigae to determine the clamping force off the grade 8 bolts(as a control group) then we did the same thing with some grade 5 bolts that had been cryogenic tempered. the grad 5 bolts actually transfered more clamping pressure to the plastigage than the grade 8 bolts did because of bolt stretch. Not that a grd 5 is a replacement for grd 8 (sheer and torsional couldnt be tested by us at that time ) but it was only to show the metaurogical (sic) change by the cryoprocess without becoming brittle. Thats it in a nut shell as i dont want to write a report on it as I say it was a laymans demo but i thot interesting . Also worked on golf balls too by gaining approx 35 yards longer drives ...LOL