we currently have a project with slip critical bolted connections that we may have to stack as many as 3 -5 washers at the nut to be able to keep threads out of the shear plain

The connection is detailed to keep the threads out of the full material plain  ,not just the shear plain  so we may end up with bolt shoulder sticking out of the connection 1/8" to 3/8" or more

Hex bolts and washers are A325   7/8" diameter galvanized

my question is what is the maximum  amount of washers you are allowed to stack ,and how does stacking washers effect the torquing of the nut and bolt  RCSC does not seem to address the amount of washers you can stack 

Thank you for the help

Bill