Rigid Metal Conduit - Electrical Engineering

Rigid Metal Conduit (RMC) provides physical protection for cables and conductors and helps cable inside safely from mechanical damage. The table below of Rigid Table Conduit is in line with NEC.

RIGID METAL CONDUIT (RMC) CONDUIT
Metric Designation	Trade Size	Internal Diameter		Total Area 100%		60%		1 Wire 53%		2 Wires 31%		Over 2 Wires 40%
Metric Designation	Trade Size	mm	in.	mm²	in.²	mm²	in.²	mm²	in.²	mm²	in.²	mm²	in.²
16	½	16.1	0.632	204	0.314	122	0.188	108	0.166	63	0.097	82	0.126
21	¾	21.2	0.836	353	0.549	212	0.329	187	0.291	109	0.170	141	0.220
27	1	27.0	1.063	573	0.887	344	0.532	304	0.470	178	0.275	229	0.355
35	1 ¼	35.4	1.394	984	1.526	590	0.916	522	0.809	305	0.473	394	0.610
41	1 ½	41.2	1.624	1,333	2.071	800	1.243	706	1.098	413	0.642	533	0.828
53	2	52.9	2.083	2,198	3.408	1,319	2.045	1,165	1.806	681	1.056	879	1.363
63	2 ½	63.2	2.489	3,137	4.866	1,882	2.920	1,663	2.579	972	1.508	1,255	1.946
78	3	78.5	3.090	4,840	7.499	2,904	4.499	2,565	3.974	1,500	2.325	1,936	3.000
91	3 ½	90.7	3.570	6,461	10.010	3,877	6.006	3,424	5.305	2,003	3.103	2,584	4.004
103	4	102.9	4.050	8,316	12.882	4,990	7.729	4,407	6.827	2,578	3.993	3,326	5.153
129	5	128.9	5.073	13,050	20.212	7,830	12.127	6,916	10.712	4,046	6.266	5,220	8.085
155	6	154.8	6.093	18,821	29.158	11,293	17.495	9,975	15.454	5,835	9.039	7,528	11.663

Conduit is able to contain an allowable fill percent. Hence, a conduit fill chart is provide here.