Electrical Metal Tubing (EMT) - Conduits

Trade sizes and max. distance between conduit supports for Electrical Metallic Tubing (EMT) - Thinwall Conduit. Reference: NEC Article 344 and Article 358.

Conduit Trade Size (in)	Outside Diameter (mm)	Inside Diameter (in)	Outside Diameter (in)	Inside Diameter (mm)	Max Distance Between Supports - Rigid Metal/PVC (mm)	Max Distance Between Supports (ft)	Max Distance Between Supports (m)
1/2	16	0.706	0.63	17.9	17.9	10	3
3/4	21	0.922	0.827	23.4	23.4	10	3
1	27	1.163	1.063	29.5	29.5	12	3
1 1/4	35	1.510	1.378	38.4	38.4	14	5
1 1/2	41	1.740	1.610	44.2	44.2	14	5
2	53	2.197	2.087	55.8	55.8	16	5
2 1/2	63	2.875	2.726	73.0	73.0	16	6
3	78	3.500	3.366	88.9	88.9	20	6
3 1/2	91	4.000	3.858	101.6	101.6	20	7
4	103	4.500	4.331	114.3	114.3	20	7