Bolt Torque tables

Because my assembly instructions have to be very precise, I needed to find actual torque values to put in for every bolt called out in the parts lists. I also expected that there should be some restrictions on the amount of torque one should apply to screws attaching circuit boards to standoffs. Oddly, searching on torque values for circuit board assemblies produced no useful results. It seems that a few other people have had the same assumption, and when they asked the question on forums nobody else thought the question made any sense. Eventually, I found one set of tables, adapted from a Japanese standard, which listed torque values for "electronic assemblies" which seem to be simply half the standard torque values. Here is the link to that table. This table is neat because in addition to the standard and halved values, it lists tighter values for high strength bolts. Also note that aluminum bolts/threads are listed as requiring 0.5 of the standard torque:

https://mdmetric.com/tech/Standard_tightening_torque.pdf

Note that the above table give torques in Newton-meters, logically enough. To convert that to inch lbs, there are sites that have calculators like the following:

http://www.unitconversion.org/energy/newton-meters-to-inch-pounds-conversion.html

That table is from something called the "Tohnichi Torque Handbook" which comes up well in Google searches on its own. Those values are for metric bolts and screws only, however. For English bolts, I got more google hits, strangely:

Here is the one I've been using mostly, because it goes all the way down to #4 screws and gives the values in inch lbs. However, this is just a car enthusiast's blog and doesn't credit the source of the table so I should probably find a better link: http://tr6.danielsonfamily.org/TAStripTest.htm

This table references SAE values, but doesn't apply to anything smaller than 1/4-inch bolts. This is the issue I encountered for most Google hits for English bolt torques: http://www.engineershandbook.com/Tables/torque.htm

However, it looks like another page on the same site does have the smaller sizes, and also lists torques for aluminum: http://www.engineershandbook.com/Tables/torque3.htm

This presentation has a nice table on page 9 which goes all the way down to 4-40, and an appendix that shows how to derive values for yourself using formulae: http://fp.optics.arizona.edu/optomech/Fall14/Notes/18%20Fasteners.pdf