Item

Brand and index

Hd-gx-14

Hd-gm-15

Hd-gg-15

Apparent  porous  ratio

<20

<19

<18

Volume   density      g/cm³

>2.6

>2.7

>2.8

Heating linear change ratio

     %

600^oC

+0.25

+0.25

+0.15

1100^oC

+0.3

+0.3

+0.2

Normal-temp  compression strength    MPa

>85

>85

>90

Normal-temp  abrasion   (cc) 1000^oCx3h

<7

<8

<7

Thermal  conductivity, times(1000^oC,water cooling)

>18

>20

>18