TinnerFlow™Why do trapeze hangers need lock/jam nuts
1st YearHangers, Supports & AnchorsCheck first
Single nuts can walk under vibration. Use the proper support nut and lock/jam-nut setup at the rod/strut connection per shop standard.
Plain-English answer
You assemble a dual-rod Unistrut trapeze hanger bracket on the ground, threading the lower nuts tightly onto the bottom of the strut rail, but you forget to install the secondary top backing jam-nuts against the channel face.
Single nuts can walk under vibration. Use the proper support nut and lock/jam-nut setup at the rod/strut connection per shop standard. The likely recovery is to check the condition, correct prep/setup if it is within your assignment, and bring the foreman clean information before the work creates rework overhead.
Ask Foreman
You missed the top jam-nuts on those trapeze rods. Fan vibration will cause those single nuts to slowly back off and sag the duct. Double-nut every connection point to lock those rails solid.
Verify before acting
Use this as training guidance. Foreman direction, approved drawings, project specs, manufacturer instructions, employer safety policy, and AHJ/code requirements always control the final answer.
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