Torque Tube Bolts

[Conaway2]

Still rebuilding the rear axle, and ran into a couple of questions yesterday when I disassembled the banjo and torque tube. 5 of the 6 bolts appear original, in that they have holes for safety wire and have a shoulder just below the bolt head. The 6th bolt had no hole and also had a lock washer.

My questions -
Were lockwashers used on these bolts ?

Do these bolts have the special thread pitch like the axle housing bolts do ?

Were these bolts plated or painted when new ?

Many thanks
Jim