MECHANICAL SEAL HARD FACE MATERIALS

Hard Face Material

Hardness

Elastic Modulus E

Tensile Strength

Thermal Expansion

Thermal Conductivity

Density

Temperature Limit

Coeff.of Friction

Mohs

GN/m2

MN/m2

µm/mK

Watts/m°K

mg/mm3

°C(a)

vs. Carbon

Gray cast iron

5

100

200

10

45

7.2

200

-

Hastelloy "B"

6

230

1300

18

45

8.9

800

-

M-2 Tool steel

7

200

2000

11

25

8.2

500

-

Niresist

4

100

400

18

15

7.4

500

-

316 Stainless

4

200

600

16

16

8

600

-

440C Stainless

5

200

800

10

25

7.8

600

-

Stellite

7

220

1000

14

15

8.4

1000

-

T/C - Cobalt

8

600

1400

4

100

15

400

0.07

T/C - Nickle

8

600

600

5

90

15

250

0.07

Ceramic 85%

8

200

150

5

12

3.4

1400

0.07

Ceramic 99.5%

8

350

250

7

25

3.9

1700

0.07

SiC Alpha Sintered

9.7

400

250

4

130

3.1

1000

0.02

Sic Reaction Bonded

9.7

400

250

4

150

3.1

1000

0.02

(a) Severe oxidation in air, or significant loss of hardness, or changed microstructure.

Hard Face Material

Vickers

N/mm2

Watts/m°C

Gm/cc.

°C(a)

Siliconized graphite

PE-8148

2000

16

50

1.95

232

Reaction Bonded

PR9242

2400

365

145

3.08

1372

Reaction Bonded

plus graphite PG9723

152

153

2.8

538

Alpha sintered

PS-10070

3000

400

130

3.1

1649

PS-10138

3000

407

130

3.1

1649

 

Link to Mc Nally home page