Torque Settings

[Richard S]

I’ve rebuilt a number of engines and have always understood that specified torque settings were to be used on clean dry bolts. 
 
Dr Benz recently advised that the BBB specified that head bolts were to be oiled on the threads and under the bolt head before torqueing.  I checked and he is correct (no surprise there) but this is the first and only time that I have ever seen this specified in any rebuild manual and is not specified in the BBB for any other torque settings other than head bolts.

I’ve a chart which specifies torque settings for both lubricated and dry bolts, and the lubricated torques are about 20% less than unlubricated settings.  The chart also states “Using dry-bolt specs on a lubricated bolt…will over torque the bolt and stretch, or perhaps even weaken or break it.”

So….am I correct that torque settings are normally done dry, unless specified otherwise?

[Benz Dr.]

How can you over torque something using a proper torque wrench?

  I always oil head bolts regardless of what I'm working on. During a re-torque, there won't be that much oil left on the threads and yet the screw will turn about a 1/16th to 1/8th of a turn further than where it was initially set.