Physical Property

No.

Physical performance

Numerical Value

Unit

1

Coefficient of mean linear thermal expansion(20℃,300℃)

3.3±0.1

10-6K-1

2

Transformation temperature

525±15

℃

3

Softening point

820±10

℃

4

Working point

1260±20

℃

5

Density at 20℃

2.23±0.02

g/cm3

6

Mean thermal conductivity(20℃-100℃)

1.2

w/m2k

7

Refractive index

0.92

1

Main Composition

SiO2

B2O3

Na2O+K2O

Al2O3

81

13

4

2

Chemical Property

Hydrolytic resistance at 98℃

ISO719-HGB 1

Hydrolytic resistance at 121℃

ISO720-HGA 1

Acid resistance Class

ISO1776-First Class

Solid Rod

Size(mm)

Diameter

Deviation

Roundness

Straightness

4

±0.30

0.30

3‰

6

±0.30

0.30

3‰

7

±0.30

0.30

3‰

8

±0.40

0.40

3‰

9

±0.40

0.40

3‰

10

±0.40

0.40

3‰

11

±0.50

0.50

3‰

12

±0.50

0.50

3‰

14

±0.60

0.60

3‰

16

±0.70

0.70

3‰

18

±0.80

0.80

3‰

20

±0.90

0.90

3‰

22

±1.10

1.10

3‰

24

±1.20

1.20

3‰

26

±1.30

1.30

3‰

28

±1.40

1.40

3‰

30

±1.50

1.50

3‰

32

±1.70

1.70

3‰

We also can manufacture customized sizes.