Structural Bolt Inspection & Replacement Guide
Fasteners are only as good as their grade, their installation, and their condition. Here's how to identify, inspect, and decide when to retire structural bolts.
Know the grade
Common structural bolts (formerly A325 and A490) are now covered under ASTM F3125. Grade is identified by head markings, and bolts must be matched with the correct nut and washer. Record the grade and coating so replacements match exactly.
Inspection points
- Corrosion, pitting, or coating breakdown
- Damaged, stripped, or galled threads
- Nuts that have loosened or backed off, or joints that are no longer snug-tight / properly tensioned
- Signs of overload such as visible stretch or necking
When to replace
Retire bolts that are corroded or pitted, have damaged threads, or show any sign of stretch or overload. Pretensioned high-strength bolts (for example those installed by turn-of-nut) generally should not be reused once they've been tensioned — replace rather than re-torque.
Keep the record
Log grade, coating, size, installation date, and the tensioning method used. That history is what lets you prove the joint was built correctly and plan replacements before a problem appears.
Stay ahead of every replacement
TexTrack tracks every bolt and fastener you supply and reminds you and your customer before it's due. See maintenance management software for parts suppliers.
General guidance only. Follow the RCSC specification for structural joints, the bolt manufacturer's instructions, and the direction of the engineer of record for any structural connection.