Using some method of determining the amount of friction which the bolt is requiring to turn it is very important to gasket and machine performance....... The amount of area rubbing together when you figure the sides of the threads gets large fast...as you screw it in.... Not only does it need to be measured but you can not measure anything relavant unless the THREADS ARE CLEAN AND 'LIGHTLY' LUBRICATED.... this is the standard way engineers measure this....it is important because you are not actually measureing the HOLD DOWN AMOUNT of the article being bolted on.... rather a hoperfully ' translates to' amount based on trials of similar tries in the past.... You can be using a million dollar torque wrench and one bit of maching tailing or broken thread off the last bolt cause you to get NO pull down at that location... even though the torque wrench WILL READ PERFECTLY.... as if you are set to go.... \
Therefore, it is important that one use a torque wrench AND have a clean and lightly lubed thread surface...... DON'T ARGUE WITH ME ON THIS,, TO SAVE FUTURE EMBARRASSMENT.... LOL....
The only way to do this properly... and I always do it on any head gasket situation .... is to invest in the proper tap and die for the hole you are working on... and learn to use it properly.... so as not to have to learn how to drill out a broken tap.... NO LOL.. If you are interested in this sort of stuff I suggest the three ' Machinist Bedside Readers" by Guy Latuard....... Greg