Joe,
There is a big difference in the threads on the various brands of conduit bodies and conduit. Just because there are a number of threads showing does not mean that the joint has not been made up tight. Some combinations produce a "wrench tight" condition with only 3 or 4 male threads engaged in the fitting.
I do have a problem with the bonding at our conduit couplings. The fact that they are straight thread makes for a poor bonding connection, in my opinion. I think that if our conduit couplings were tapered thread like plumbing couplings, the bonding would be much better.
Don
