B-2 STANDARD BOLT TORQUE SPECIFICATIONS STANDARD BOLT TORQUE SPECIFICATIONS HOW TO DETERMINE BOLT STRENGTH Hexagon head bolt Mark Bolt head No. 4- 5- 6- 7- Class 4T 5T 6T 7T Stud bolt Mark No mark Class 4T No mark 4T Hexagon flange bolt w/washer hexagon bolt No mark 4T Grooved 6T Hexagon head bolt Two protruding lines 5T Hexagon flange bolt w/washer hexagon bolt Two protruding lines 6T Welded bolt 4T Hexagon head bolt Three protruding lines 7T