Hemispherical Emissivities of Various Surfaces Table

Related Resources: heat transfer

Material	Wavelength and Average Temperature
Material	9.3 mm 310 K	5.4 mm 530 K	3.6 mm 800 K	1.8 mm 1700 K	0.6 mm Solar ~6,000 K
Aluminum
polished	~0.04	0.05	0.08	~0.19	~0.30
oxidized	0.11	~0.12	0.18	-	-
24-ST weathered	0.40	0.32	0.27	-	-
surface rooﬁng	0.22	-	-	-	-
anodized (at 1,000°F)	0.94	0.42	0.60	0.34	-
Brass
polished	0.10	0.10	-	-	-
oxidized	0.61	-	-	-	-
Chromium
polished	~0.08	~0.17	0.26	~0.40	0.49
Copper
polished	0.04	0.05	~0.18	~0.17	-
oxidized	0.87	0.83	0.77	-	-
Iron
polished	0.06	0.08	0.13	0.25	0.45
cast, oxidized	0.63	0.66	0.76	-
galvanized, new	0.23	-	-	0.42	-
galvanized, dirty	0.28	-	-	0.90	0.66
steel plate, rough	0.94	0.97	0.98	-	0.89
oxide	0.96	-	0.85	-	0.74
molten	-	-	-	0.3 – 0.4	-
Magnesium	0.07	0.13	0.18	0.24	0.30
Molybdenum ﬁlament	-	-	~0.09	~0.15	~0.20
Silver
polished	0.01	0.02	0.03	-	0.11
Stainless steel
18-8, polished	0.15	0.18	0.22	-	-
18-8, weathered	0.85	0.85	0.85	-	-
Steel tube
oxidized	-	0.94	-	-	-
Tungsten ﬁlament	0.03	-	-	~0.18	0.35
Zinc
polished	0.02	0.03	0.04	0.06	0.46
galvanized sheet	~0.25	-	-	-	-
Building and Insulating Materials
Asbestos paper	0.93	0.93	-	-	-
Asphalt	0.93	-	0.90	-	0.93
Brick
red	0.93	-	-	-	0.70
ﬁre clay	0.90	~0.70	~0.75	-	-
silica	0.90	0.75	0.84	-	-
magnesite refractory	0.90	-	~0.40		-
Enamel, white	0.90	-	-		-
Marble, white	0.95	0.93	-		0.47
Paper, white	0.95	0.82	0.25		0.28
Plaster	0.91	-	-		-
Rooﬁng board	0.93	-	-	-	-
Enameled steel, white	-	-	-	0.65	0.47
Asbestos cement, red	-	-	-	0.67	0.66