Rigid Nonmetallic Conduit
Typical Properties of Conduit Raw Material Compound
Thermal
Mechanical
ASTM
Test
Typical Values
D696
3.38 x 10-5
D648
160 °F
N/A
1.3
Co-efficient of Thermal
Expansion (inch/inch/°F)
(properties @ 73.4°F)
Heat Distortion (°F at 264 psi)
Thermal Conductivity
(BTU in/hour/square foot/°F)
Electrical
Specific Gravity
Tensile Strength (psi) @ 73.4°F
Izod Impact (ft lbs./in. of notch)
Flexural Strength (psi)
Compressive Strength (psi)
Hardness (Durometer D)
ASTM
Test
D792
D638
D256
D790
D695
D2240
Typical
Values
1.43 - 1.6
5,000 - 6,500
0.65 - 1.5
12,500
9,000
85
Impedance
Dielectrical Strength (volts/mil)
Dielectric Constant (60 CPS @ 30°C)
Power Factor (60 CPS @ 30°C)
ASTM
Test
D149
D150
D150
Typical
Values
1100
4.00
1.93
Steel Conduit
Schedule 40
3 90%
P.F.
0.0118
0.0105
80%
P.F.
0.0123
0.0106
1 90%
P.F.
0.0136
0.0121
80%
P.F.
0.0142
0.0122
Using 250 kcmil copper conductor comparable values for other
conductor sizes.
Wirefill
Per NEC 352.22: Number of Conductors. The number of conductors shall not exceed that permitted by the percentage fill specified
in Table 1, Chapter 9.
Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of
cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.
NEC Chapter 9, Table 1: Percent of Cross Section of Conduit and Tubing for Conductors
Number of Conductors
1
2
Over 2
All Conductor Types
53
31
40
Read all notes following Chapter 9, Table 1 in the National Electrical Code for complete information and explanation. Conduit and
Tubing Fill Tables for Conductors and Fixture Wires of the Same Size for Schedule 40, Schedule 80, and Type EB PVC Conduit is
located in the Informative Annex C of the NEC.
Weight Comparison
Prime Conduit Schedule 40 rigid nonmetallic conduit compared to other rigid conduit in pounds per 100 feet (approx.)
Nom.
Size
1/2
3/4
1
1-1/4
1-1/2
2
2-1/2
3
3-1/2
4
5
6
Prime Conduit
Sch. 40 RNC
17
23
34
46
55
73
124
163
196
232
315
409
Prime Conduit
Sch. 80 RNC
21
30
44
60
72
101
154
210
308
428
588
Aluminum
27
36
53
70
86
116
183
239
288
340
465
612
Electrical Metallic
Conduit (EMT)
30
46
66
96
112
142
230
270
350
400
Not Made
Not Made
23240 Chagrin Blvd Suite 405  Cleveland, OH 44122  216-464-3400  www.primeconduit.com
Intermediate Metal
Conduit (IMC)
57
78
112
114
176
230
393
483
561
625
Not Made
Not Made
Rigid Metal
Conduit (RMC)
79
105
153
201
246
334
527
690
831
982
1344
1770
1