A325 Structural Bolts

When purchasing bolting fasteners for structural use, the following are highly recommended topics to take into consideration:- Stable torque-tension relationship in-between- Nut lubrication to the torque co-efficient- Purchase sets assembled; do not purchase bolts/nuts/washers separately unless you are well equipped with quality assurance personnel and testing equipmentsConsider no guess-work towards how much torque could result in tension of bolt set, and although they are within range, how could you maintain an acceptable range of bolt set that clamping force could be unique without shear force occurs.Visual check of torshear bolt sets with end spline pulled/sheared off could guarantee tightening capability, where turn-of-nut measurement would be the only way for normal structure bolt (no spline end) as per norms specified for both the post load turning angles and stable torque-tension.