bolted connections threads

huangyhg

bolted connections & threads
what is the rule of thumb of how many threads on the bolt should be past the face of the nut in bolted connections for steel framing?
i found the answer once some time ago and misplaced that tibbit.
thanks in advance.
2 (i think you mean exposed threads)
for standard structural nuts and bolts, no "stick-thru" is required.  the end of the nut must only be flush with the end of the bolt.  
for self-drilling screws in light-gauge steel, three threads need to be exposed beyond the parts connected.
this is for building construction per aisc and aisi and manufacturer recommendations.  these may be different for other applications or disciplines.