Shaker Screen bolts are Self-anchoring bolts with a square neck that resists turning when nut is tightened or removed. This bolt is stronger than a carriage bolt, and is always fully threaded. Most commonly used for wood-to-wood and wood-to-metal applications. Plain finish, or bare metal, may or may not have a coating of light oil to resist corrosion. Grade 8 has a greater tensile strength than Grade 5.