By Blissom · Updated 2026-11-04
Strap spacing for every raceway (NEC 2023)
| Raceway | Section | Within, from boxes and terminations | Max between supports |
|---|---|---|---|
| EMT | 358.30 | 3 ft (5 ft where framing does not permit, unbroken lengths) | 10 ft |
| Rigid (RMC) | 344.30 | 3 ft (5 ft where framing does not permit) | 10 ft; up to 20 ft on straight threaded runs (table below) |
| IMC | 342.30 | 3 ft (5 ft where framing does not permit) | Same as RMC |
| PVC | 352.30 | 3 ft | 3 ft to 8 ft by trade size (table below) |
| Flex (FMC) | 348.30 | 12 in | 4-1/2 ft |
| Liquidtight flex (LFMC) | 350.30 | 12 in | 4-1/2 ft |
| Liquidtight nonmetallic (LFNC) | 356.30 | 12 in each side of boxes | 3 ft |
| ENT | 362.30 | 3 ft | 3 ft |
"Termination" covers outlet, junction and device boxes, cabinets, conduit bodies and fittings where the raceway ends. Check which NEC edition your inspector enforces; local amendments can be stricter.
EMT: 358.30
358.30(A): securely fastened within 3 ft of each outlet box, junction box, device box, cabinet, conduit body or other tubing termination, and at intervals not exceeding 10 ft.
The 5 ft exception: where structural members do not readily permit fastening within 3 ft, an unbroken length may be fastened within 5 ft of the termination. Unbroken means no coupling in that length. It is for a box between joists or studs where the nearest solid backing is out of reach, not for saving a strap.
358.30(B): horizontal runs through openings in framing members, at intervals not exceeding 10 ft, are considered supported, provided the EMT is securely fastened within 3 ft of terminations.
Rigid (RMC) and IMC: 344.30 and 342.30
Same start as EMT: within 3 ft of each termination (5 ft where structural members do not permit) and every 10 ft. The difference is 344.30(B)(2): straight runs made up with threaded couplings may stretch the spacing to the values below, as long as the supports keep the run from transmitting stress to the terminations. IMC follows the same rules and table.
| Trade size | Max between supports, straight threaded runs |
|---|---|
| 1/2–3/4 | 10 ft |
| 1 | 12 ft |
| 1-1/4–1-1/2 | 14 ft |
| 2–2-1/2 | 16 ft |
| 3 and larger | 20 ft |
Threadless compression or set-screw couplings on a rigid run do not qualify for the table; use 10 ft.
PVC: 352.30
Within 3 ft of each outlet box, junction box, device box, conduit body or other termination, then no more than the spacing in Table 352.30. PVC sags between supports when it is warm, which is why the small sizes need so many straps.
| Trade size | Max between supports |
|---|---|
| 1/2–1 | 3 ft |
| 1-1/4–2 | 5 ft |
| 2-1/2–3 | 6 ft |
| 3-1/2–5 | 7 ft |
| 6 | 8 ft |
Outdoors, the straps also have to let the conduit slide toward its expansion fittings; see the PVC expansion calculator.
Flex, liquidtight and ENT
- FMC (348.30) and LFMC (350.30): within 12 in of each box, cabinet, conduit body or other termination, and at intervals not exceeding 4-1/2 ft. Both sections have exceptions: lengths at terminals where flexibility is necessary, and lengths from the last support to a luminaire or other equipment in an accessible ceiling. The permitted lengths differ by trade size and edition, so read the exception text before leaving a long whip unsupported.
- LFNC (356.30): secured within 12 in on each side of boxes and at intervals not exceeding 3 ft, with exceptions in 356.30 where flexibility is needed.
- ENT (362.30): secured within 3 ft of each termination and at intervals not exceeding 3 ft.
Horizontal runs through framing
EMT run through bored or punched holes in studs or joists counts as supported when the holes are no more than 10 ft apart (358.30(B)). Rigid and IMC get the same allowance: openings no more than 10 ft apart and a fastener within 3 ft of each termination (344.30(B)(4), 342.30(B)(4)). PVC gets it too, but the openings may be no farther apart than the Table 352.30 spacing for its size, so 3 ft for 1/2" to 1" PVC (352.30(B)).
What the framing does not do is replace the strap at the box. The last support before every box still has to be a fastener within 3 ft. A box fed only through a bored stud, with no strap, does not meet it.
How many straps a run needs
For a run between two boxes: one strap within the end distance of each box, then enough intermediate straps that no gap exceeds the maximum. Couplings between 10 ft sticks do not need their own strap, but placing one near each coupling keeps a long run straight.
Worked example: 40 ft of EMT between two boxes
- Strap within 3 ft of each box: one at 3 ft, one at 37 ft.
- Between them: 37 − 3 = 34 ft. At 10 ft maximum that is 34 ÷ 10 = 3.4, rounded up to 4 gaps, so 3 intermediate straps (for example at 11.5, 20 and 28.5 ft).
- Total: 5 straps. The same 40 ft in 3/4" PVC (3 ft spacing) needs 13.
Minimum straps for a run between two terminations
| Run | EMT / RMC every 10 ft | 1" RMC, threaded, 12 ft | 3/4" PVC, 3 ft | 2" PVC, 5 ft | FMC, 4-1/2 ft |
|---|---|---|---|---|---|
| 10 ft | 2 | 2 | 3 | 2 | 3 |
| 20 ft | 3 | 3 | 6 | 4 | 5 |
| 30 ft | 4 | 3 | 9 | 6 | 8 |
| 40 ft | 5 | 4 | 13 | 8 | 10 |
| 50 ft | 6 | 5 | 16 | 10 | 12 |
| 60 ft | 7 | 6 | 19 | 12 | 14 |
| 80 ft | 9 | 8 | 26 | 16 | 19 |
| 100 ft | 11 | 9 | 33 | 20 | 23 |
Assumes end straps placed at the full end distance (3 ft, or 12 in for flex) and no exceptions. Bends, offsets and changes of direction usually add straps where the conduit leaves the wall or ceiling.
On a single 10 ft stick of EMT from a box: a strap within 3 ft of the box, and the next support within 10 ft of it. A strap a foot or two from the box and one near the far coupling covers it with room to spare.
What inspectors write up
- First strap too far from the box. 3 ft for EMT, rigid, IMC and PVC; 12 in for flex.
- Using the 5 ft exception without a reason. It applies only where structural members do not readily permit fastening within 3 ft, and only to unbroken lengths.
- Small PVC strapped like EMT. 3/4" PVC at 10 ft spacing is more than three times the Table 352.30 maximum.
- Rigid spaced from the table with set-screw couplings. The longer spacing needs threaded couplings on a straight run.
- Flex left hanging. Long whips without support beyond what the exception allows, or no strap within 12 in of the box.
- Conduit hung from ceiling grid wires. Raceways above a suspended ceiling need their own support, not the ceiling's (300.11).
- Too many bends between boxes. Not a strapping issue, but often found on the same walk; see the 360° rule.
Sources: NEC 2023: 358.30 (EMT), 344.30 and Table 344.30(B)(2) (RMC), 342.30 (IMC), 352.30 and Table 352.30 (PVC), 348.30 (FMC), 350.30 (LFMC), 356.30 (LFNC), 362.30 (ENT). Method.
Questions electricians ask
How far from a box does EMT need to be strapped?
Within 3 ft of each outlet box, junction box, device box, cabinet, conduit body or other termination (358.30(A)). Where structural members do not readily permit it, an unbroken length can be fastened within 5 ft.
What is the maximum EMT support spacing?
10 ft between supports (358.30(A)). Horizontal runs through holes in framing members at intervals of 10 ft or less count as supported, as long as the tubing is fastened within 3 ft of terminations.
How far apart do PVC conduit straps go?
Table 352.30: 3 ft for 1/2" to 1", 5 ft for 1-1/4" to 2", 6 ft for 2-1/2" and 3", 7 ft for 3-1/2" to 5", 8 ft for 6". Plus a strap within 3 ft of each termination.
What is the support spacing for rigid conduit?
Within 3 ft of each termination and every 10 ft. Straight runs made up with threaded couplings may use Table 344.30(B)(2): up to 12 ft for 1", 14 ft for 1-1/4" and 1-1/2", 16 ft for 2" and 2-1/2", 20 ft for 3" and larger.
How far apart do you strap flexible conduit?
FMC and LFMC: within 12 in of each box or termination and at intervals of no more than 4-1/2 ft. There are exceptions for short lengths where flexibility is needed and for luminaire whips in accessible ceilings; read 348.30 and 350.30 for the exact lengths.
Does a coupling or connector count as a support?
No. A box connector is the termination the strap is measured from, and couplings are not supports. The strap has to be a separate fastener.
Bend it right, then strap it right
- NEC conduit fill and box fill
- Every bend: offsets, saddles, kicks, 90s, segmented
- Marks from the end of the conduit
- Offline on the job
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