Machinable graphite

Machinable graphite

Machinable graphite is known for its excellent isostatic qualities and its perfect homogeneity. It does not absorb moisture, deform, burst or shrink due to thermal stress.

Graphite offers optimal resistance at very high temperatures and in highly corrosive environments. Heat losses are minimalized and thermal conduction optimized. Graphite is self-lubricating and easily machinable.

Graphite, an essential material for the production of silicon, is widely used in the production of semiconductors. It is also an essential material for different dedicated machining solutions in the industries of plastic processing, glass manufacturing, metallurgy and even as an insulating material for furnaces.

Applications

Graphite is used for the handling, machining and shaping of heated glass.

Machinable graphite is an indispensable material for the manufacture of tools for the transformation of heated glass.

Final offers a full range of materials and processes for the transformation of glass. With our extensive experience and know-how in this field, we are able to provide a full range of solutions for processes involving a number of metallic or composite tools using graphite.

Graphite machining

Graphite can be manufactured through extrusion or isostatic pressing.

  • HLM : Extruded graphite, standard particle size

  • HLR : HLM lower quality with higher porosity

  • R7340 : Isostatic standard

  • R7340P30 : Equivalent to R7340 with greater purity and an ash content less than 30 ppm

  • R4550 : Isostatic, fine particle size and very high mechanical strength.

  • R6650 : Isostatic, fine particle size and very high mechanical strength, exceeding those of R4550

  • R6650P5 : Equivalent to R6650, very high purity, ash content less than 5ppm.

  • R6710 : Isostatic, ultra-fine particle size and excellent mechanical strength

  • R6710P5 : Equivalent to R7340, very high purity, ash content less than 5 ppm suitable for semiconductor manufacturing.

After machining, isostatic graphite has a surface roughness of 0,6µm.

Technical data

 

EXTRUSION

ISOSTATIC PRESSING

REFERENCES

HLM

R4550

R6650

R6710

R7340

Direction as per grain length

//

// and 

// and 

// and 

// and

Density

g/cm3

1.7

1.83

1.84

1.88

1.72

Max. particle size

mm

0.8

0.01

0.007

0.003

0.015

Open porosity 

%

17

10

10

10

15

Electrical resistivity

Ohm.cm

7.3.10-4

9.4.10-4

13.10-4

14.10-4

13.10-4

12.10-4

Young’s modulus 

GPa

10

9

11.5

12.5

13.5

10.5

Flexural strength

MPa

18

17

60

65

85

45

Compressive strength

MPa

39

35

125

150

240

90

Tensile strength

MPa

13

12

/

/

/

/

Hardness

 

Shore 20-25

(Shore D 70)

Rockwell B

95

Rockwell B

95

Rockwell B 110

Rockwell B 80

Thermal expansion (20/200°C)

10-6.K-1

2.1

3.1

4

3.9

4.7

2.9

Thermal conductivity

W/m.K

180

140

100

90

100

90

Ash content

%

< 0.1

0.002

/

/

0.02

For the R7340 reference, we supply a wide range of bars directly extruded in a selection of standard diameters representing a significant cost-saving to the customer as the bars require no preparatory machining. These 300- mm. bars are available in the following diameters :

Ø 3.2 - Ø 4.8 - Ø 6.4 - Ø 7.9 - Ø 9.5 - Ø 12.7 - Ø 13.8 - Ø 16 - Ø 19 mm

Advantages

  • They resist thermal shocks,
  • They do not adhere to glass,
  • They avoid mechanical tension in glass and prevent scratches on hot glass,
  • They feature low wear and friction coefficients, with positive thermal conductivity.

Our graphite-metal or graphite -composite tooling can increase the productivity of your production lines. They will make the set-up, settings and the maintenance of your production tools easier and quicker.

Blown glass

Final machines graphite moulds for glass casting and blow moulding.

  • Fixture and insertion mechanisms
  • Support plates, guides, handling mechanisms
  • Transfer wheels and rotary plates
  • Smelting crucibles
  • Press tools
  • Furnace insulation

Contact us for more informations about graphite machining.

Graphite (1.11M)

Technical data sheet graphite.