342.29 Threads entering enclosures
What changed in 342.29
Where IMC threads enter an enclosure through an unthreaded opening, new 342.29 calls for a locknut or listed fitting on both sides of the wall. RMC got the same rule in 344.29.
Point by point
- Where IMC threads pass through an unthreaded hole in an enclosure, put a locknut inside and another outside.
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Get the whole breakdown
- 3 more points on exactly what changed
- The 2023 rule next to the 2026 rule, side by side
- Why it changed
- What to do and check on the job
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This section across NEC® editions
2020 NEC®No change
This section did not change from 2017 to 2020.
2023 NEC®No change
This section did not change from 2020 to 2023.
2026 NEC®NewYou're here
Where IMC threads enter an enclosure through an unthreaded opening, new 342.29 calls for a locknut or listed fitting on both sides of the wall. RMC got the same rule in 344.29.
More 2026 changes in Article 342
This is a plain-English summary, not the NEC®'s exact wording. Always check the full section in the NEC® edition your area has adopted, plus any local amendments.
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