For 24 gauge sheet metal using a button strap lock, what is the standard pocket depth?

• A. 1/4 inch
• B. 3/8 inch
• C. 1/2 inch
• D. 5/8 inch

Answer: (C)

Pocket depth in a button strap lock is how far back the folded metal forms a recessed area for the strap to lock into. For 24 gauge sheet metal, the standard practice is about one-half inch. This depth provides enough material behind the seam so the interlocking strap can engage securely and resist pulling apart, while not being so deep that forming the seam causes distortion or makes assembly awkward. If the pocket is shallower, the lock may not fully engage and could loosen under service conditions. If it’s deeper, it can complicate forming and introduce unnecessary stress or misalignment. Therefore, one-half inch is the typical, best-followed depth.