MATERIAL C EMISSIVITY

Alloys:  Nicket-Chromium 

20Ni-25Cr-55Fe, Oxidized

200

0.90

60Ni-12Cr-28Fe, Oxidized

270

0.89

80Ni-20Cr

100

0.87

Aluminum: 

Polished

50-500

0.04-0.06

Rough Surfaces

20-50

0.06-0.07

Strongly Oxidized

55-500

0.2-0.3

Oxidized

200

0.11

Asbestos Boards

20

0.96

Bismuth, Oxidized

25

0.048

Brass: 

Dull, Tarnished

200

0.61

Oxidized @ 600˚C

200

0.61

Unoxidized

25

0.035

Polished

200

0.03

Rolled Sheet

20

0.06

Carbon: 

Filament

1000-1400

0.53

Graphite

0-3600

0.7-0.8

Lamp Black

20-400

0.96

Soot Applied to Solid

50-1000

0.96

Soot with Water Glass

20-200

0.96

Unoxidized

100

0.81

Chromium, Polished

50

0.1

Cobalt, Unoxidized

500

0.13

Columbium, Unoxidized

1500

0.19

Copper: 

Calorized

100

0.26

Calorized, Oxidized

200

0.18

Commercial, Scoured to a Shine

20

0.07

Oxidized

50

0.6-0.7

Polished

50-100

0.02

Unoxidized

100

0.02

Unoxidized liquid

---

0.15

Fire Brick

1000

0.75

G-10 Epoxy Resin

---

0.95

Glass

20-100

0.94-0.91

Gold: 

Carefully Polished

200-600

0.02-0.03

Unoxidized

100

0.02

Enamel

100

0.37

Graphite

0-3600

0.7-0.8

Gypsum

20

0.93

Iron, Cast: 

Oxidized

200

0.64

Strongly Oxidized

40

0.95

Unoxidized

100

0.21

Unoxidized, Liquid

---

0.29

Rusted

25

0.65

Wrought, Dull

100

0.05

Lamp Black

25

0.94

Lead: 

Oxidized

200

0.96

Unoxidized

200

0.63

Mercury, Unoxidized

25

0.10

Molybdenum

600-1000

0.08-0.13

Monel, Metal Oxidized

200

0.43

Nichrom Wire: 

Clean

50

0.65

Oxidized

50-500

0.95-0.98

Nickel: 

Industrial, Polished

200-400

0.07-0.09

Oxidized

200

0.37

Oxidized @ 600˚C

200-600

0.37-0.48

Unoxidized

25

0.045

Platinum: 

Clean, Polished

200-600

0.05-0.1

Unoxidized

25

0.037

Unoxidized, Wire

50-200

0.06-0.07

Porcelain, Glazed

20

0.92

Quartz

---

0.92

Rubber: 

Hard

20

0.95

Soft, Grey, Rough

20

0.86

Silica Brick

1000

0.80

Silicon

---

0.92

Silver: 

Clean Polished

200-600

0.02-0.03

Unoxidized

100

0.02

Soot Applied to Solid Surface

50-1000

0.94-0.91

Soot with Water Glass

20-200

0.96

Steel: 

Alloyed (8% Ni, 18% Cr)

500

0.35

Aluminized

50-500

0.79

Dull Nickel Plated

20

0.11

Flat, Rough Surface

50

0.95-0.98

Cast, Polished

750-1050

0.52-0.56

Sheet, Ground

50

0.56

Oxidized

200-600

0.8

Calorized, Oxidized

200

0.52

Sheet with Shiny Layer Oxidized

20

0.82

Strongly Oxidized

50

0.88

Unoxidized

100

0.08

Unoxidized, Liquid

---

0.28

Tantalum, Oxidized

1500

0.21

Tungsten, Unoxidized

25

0.024

Varnish:

Varnish

40-100

0.8-0.95

Dull Black

40-100

0.96-0.98

Glossy Black Sprayed on Iron

20

0.87

Zinc: 

Polished

200-300

0.04-0.05