Which statement about aircraft bolts is correct?

Which statement about aircraft bolts is correct?

• A. Over-Tighten The Nut To Align The Next Cotter Pin Hole
• B. In General Bolt Grip Lengths Should Equal The Material Thickness
• C. Alloy Steel Bolts Smaller Than 1/4 Inch Diameter Should Not Be Used In Primary Structure
• D. The Torque Values For Nuts Are Always Specified

Answer: (B)

The main idea is how the bolt’s grip length relates to the parts being joined. The grip length is the portion of the bolt shank that goes through all the joined materials, and the threaded portion engages with the nut beyond those parts. The goal is for the unthreaded part to carry the shear load and for the threads to have adequate engagement in the nut to develop the clamping force. When the grip length matches the material thickness, the bolt is properly sized: the unthreaded shank sits entirely in the joined parts, and the threads are available to engage the nut without being buried in extra material or leaving insufficient thread length for the nut to grip. If the grip length were longer than the material thickness, the threaded portion could protrude into areas where it shouldn’t, risking improper engagement or interference. If the grip length were shorter, there wouldn’t be enough thread engagement with the nut, compromising clamp force and shear strength. That’s why this statement is the best: it captures the standard practice of matching grip length to material thickness to ensure proper alignment, engagement, and load transfer. The other options describe procedures or generalities that aren’t correct or universally applicable in aircraft bolt use.

The main idea is how the bolt’s grip length relates to the parts being joined. The grip length is the portion of the bolt shank that goes through all the joined materials, and the threaded portion engages with the nut beyond those parts. The goal is for the unthreaded part to carry the shear load and for the threads to have adequate engagement in the nut to develop the clamping force.

When the grip length matches the material thickness, the bolt is properly sized: the unthreaded shank sits entirely in the joined parts, and the threads are available to engage the nut without being buried in extra material or leaving insufficient thread length for the nut to grip. If the grip length were longer than the material thickness, the threaded portion could protrude into areas where it shouldn’t, risking improper engagement or interference. If the grip length were shorter, there wouldn’t be enough thread engagement with the nut, compromising clamp force and shear strength.

That’s why this statement is the best: it captures the standard practice of matching grip length to material thickness to ensure proper alignment, engagement, and load transfer. The other options describe procedures or generalities that aren’t correct or universally applicable in aircraft bolt use.