Les,
Torque is not a reliable means of achieving tension load in bolt assemblies. According to the RCSC, you can get as much as +/-40% variation from one bolt assembly to the next using torque as your installation criterion. See if you can get a copy of the Research Council on Structural...
RECENTLY, WE HAD A POTENTIAL CUSTOMER MENTION THIS STANDARD IN AN INQUIRY. DOES ANYONE KNOW WHAT THIS STANDARD COMPRISES AND WHERE I CAN GET A COPY?
JOHN HERR
APPLIED BOLTING
HERR@APPLIEDBOLTING.COM