Cut Sheet

Conduit Dimensional Data
Knockout (Sliphole) Sizes for Electrical
Conduits and Connectors
TRADE KNOCKOUT DIAMETER
SIZE (IN.) NOM. MIN. MAX.
1
⁄4 .575 .559 .605
3
⁄8 .718 .703 .734
1
⁄2 .875 .859 .906
3
⁄4 1.109 1.094 1.141
1 1.375 1.359 1.406
1
1
⁄4 1.734 1.719 1.766
1
1
⁄2 1.984 1.958 2.000
2 2.469 2.433 2.500
2
1
⁄2 2.969 2.938 3.000
3 3.594 3.563 3.625
3
1
⁄2 4.125 4.063 4.156
4 4.641 4.563 4.672
4
1
⁄2 5.109 5.063 5.166
5 5.719 5.625 5.750
6 6.813 6.700 6.844
Sizes
1
⁄ 4 " thru 1
1
⁄ 4 " are per UL 514.
Sizes
1
⁄ 2 " thru 6" per proposed revision to NEMA Engineering Bulletin No. 71, Aug. 1976.
Diameter of Liquidtight Non-Metallic
Flexible Conduit
TRADE I.D. (IN.) O.D. (IN.)
SIZE (IN.) MIN. MAX. MIN. MAX.
3
⁄8 .485 .505 .755 .775
1
⁄2 .620 .640 .910 .930
3
⁄4 .815 .835 1.150 1.170
1 1.030 1.055 1.415 1.440
1
1
⁄4 1.370 1.395 1.800 1.825
1
1
⁄2 1.585 1.620 2.045 2.080
2 2.045 2.080 2.605 2.640
UL Recommended Diameters for Liquidtight
Flexible Metal Conduit
TRADE I.D. (IN.) O.D. (IN.)
SIZE (IN.) MIN. MAX. MIN. MAX.
3
⁄8 .484 .504 .690 .710
1
⁄2 .622 .642 .820 .840
3
⁄4 .820 .840 1.030 1.050
1 1.041 1.066 1.290 1.315
1
1
⁄4 1.380 1.410 1.630 1.660
1
1
⁄2 1.575 1.600 1.865 1.900
2 2.020 2.045 2.340 2.375
2
1
⁄2 2.480 2.505 2.840 2.875
3 3.070 3.100 3.460 3.500
3
1
⁄2 3.500 3.540 3.960 4.000
4 4.000 4.040 4.460 4.500
UL Recommended Diameters for Flexible
Metal Conduit (Greenfield)
TRADE MAX. O.D. O.D. (IN.)
SIZE (IN.) (IN.) MIN. MAX.
5
⁄16 .510 .312 .393
3
⁄8 .610 .375 .645
1
⁄2 .920 .625 .835
3
⁄4 1.105 .812 —
1 1.380 1.000 —
1
1
⁄4 1.630 1.250 —
1
1
⁄2 1.950 1.500 —
2 2.450 2.000 —
2
1
⁄2 3.060 3.500 —
3 3.560 3.000 —
3
1
⁄2 4.060 3.500 —
4 4.560 4.000 —
A-168
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