Which is better for the hardware to hold together the legs of my aluminum tower sections? Galvanized or Stainless steel? Finer thread (3/8-24) or courser thread (3/8-16)? Flat washers plus lock washers and standard nuts? or flat washers and locknuts? If Locknuts, should I use the nylon insert type or the type with the indent? Advice appreciated.... Jerry K3BZ