Components

Product Selection Guide
Wire Size Chart
THHW – Indicates a
fine strand flexible wire
with thermoplastic
insulation. Moisture,
oil and acid resistant.
Rated 105°C wet or dry.
THW – Indicates a
single conductor
having flame-retardant,
moisture and
heat-resistant
thermoplastic insulation.
The wire is rated 75°C
wet or dry.
TW – Indicates a
single conductor
having flame-retardant,
moisture-resistant
thermoplastic
insulation. The wire is
rated 60°C wet or dry.
TFN – Indicates a
thermoplastic-insulated
wire. The wire is rated
at a 90°C maximum
operating temperature.
THHN – Indicates a
single conductor
having flame-retardant
and heat-resistant
thermoplastic
insulation with a jacket
of extruded nylon or
equivalent material.
The wire is rated
90°C dry only.
THWN – Indicates a
single conductor
having flame-retardant,
moisture and
heat-resistant
thermoplastic insulation
with a jacket of
extruded nylon or
equivalent material.
The wire is rated 75°C
wet or dry. THWN wire
suitable for exposure to
mineral oil and to liquid
gasoline and gasoline
vapors at ordinary
ambient temperature
is marked “Gasoline
and Oil Resistant I” if
suitable for exposure
to mineral oil at 60°C,
or “Gasoline and Oil
Resistant II” if the
compound is suitable
for exposure to mineral
oil at 75°C. Gasoline-
resistant wire has been
tested at 23°C when
immersed in gasoline.
It is considered
inherently resistant to
gasoline vapors within
the limits of the
temperature rating.
Approximate Wire Outside Diameter In. (mm)
Size
With THW/
THHW/TW
Insulation
WIth TFN/
THHN/THWN
Insulation
Uninsulated Conductors, Range
Min. Max.
24 AWG 0.059 (1.5) 0.088 (2.2) 0.020 (0.5) 0.024 (0.6)
22 AWG 0.066 (1.7) 0.094 (2.4) 0.025 (0.6) 0.031 (0.8)
20 AWG 0.071 (1.8) 0.101 (2.6) 0.032 (0.8) 0.038 (1.0)
18 AWG 0.084 (2.1) 0.111 (2.8) 0.040 (1.0) 0.049 (1.2)
16 AWG 0.096 (2.4) 0.124 (3.1) 0.051 (1.3) 0.060 (1.5)
14 AWG 0.111 (2.8) 0.133 (3.4) 0.064 (1.6) 0.073 (1.9)
12 AWG 0.130 (3.3) 0.152 (3.9) 0.081 (2.1) 0.095 (2.4)
10 AWG 0.164 (4.2) 0.176 (4.5) 0.102 (2.6) 0.116 (2.9)
8 AWG 0.216 (5.5) 0.236 (6.0) 0.128 (3.3) 0.146 (3.7)
6 AWG 0.254 (6.5) 0.304 (7.7) 0.162 (4.1) 0.184 (4.7)
4 AWG 0.324 (8.2) 0.352 (8.9) 0.204 (5.2) 0.232 (5.9)
3 AWG 0.352 (8.9) 0.380 (9.7) 0.229 (5.8) 0.260 (6.6)
2 AWG 0.384 (9.8) 0.420 (10.7) 0.258 (6.6) 0.292 (7.4)
1 AWG 0.446 (11.3) 0.492 (12.5) 0.289 (7.3) 0.332 (8.4)
1/0 0.486 (12.3) 0.532 (13.5) 0.325 (8.3) 0.373 (9.5)
2/0 0.532 (13.5) 0.578 (14.7) 0.365 (9.3) 0.418 (10.6)
3/0 0.584 (14.8) 0.630 (16.0) 0.410 (10.4) 0.470 (11.9)
4/0 0.642 (16.3) 0.688 (17.5) 0.460 (11.7) 0.528 (13.4)
250 MCM 0.711 (18.1) 0.765 (19.4) 0.500 (12.7) 0.575 (14.6)
300 MCM 0.766 (19.5) 0.820 (20.8) 0.548 (13.9) 0.630 (16.0)
350 MCM 0.817 (20.8) 0.871 (22.1) 0.592 (15.0) 0.681 (17.3)
400 MCM 0.864 (21.9) 0.918 (23.3) 0.633 (16.1) 0.728 (18.5)
500 MCM 0.949 (24.1) 1.003 (25.5) 0.707 (18.0) 0.813 (20.7)
600 MCM 1.051 (26.7) 1.113 (28.3) 0.775 (19.7) 0.893 (22.7)
700 MCM 1.122 (28.5) 1.184 (30.1) 0.837 (21.3) 0.964 (24.5)
750 MCM 1.156 (29.4) 1.218 (30.9) 0.866 (22.0) 0.998 (25.3)
800 MCM 1.188 (30.2) 1.250 (31.8) 0.894 (22.7) 1.031 (26.2)
900 MCM 1.252 (31.8) 1.314 (33.4) 0.949 (24.1) 1.093 (27.8)
1000 MCM 1.310 (33.3) 1.372 (34.8) 1.000 (25.4) 1.152 (29.3)
1250 MCM — 1.539 (39.1) 1.121 (28.5) 1.289 (32.7)
1500 MCM — 1.662 (42.2) 1.228 (31.2) 1.412 (35.9)
1750 MCM — 1.776 (45.1) 1.327 (33.7) 1.526 (38.8)
2000 MCM — 1.882 (47.8) 1.419 (36.0) 1.632 (41.5)