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Grade Chart

Typical Properties of POCO Grades
Grade SFG DFP HPD TRA CZR SCF PLS
Particle Size
microns 1 4 5 5 6 6 10
µ·inches 40 160 200 200 240 240 400
Coefficient of Thermal Expansion
microns/m °C 8.1 8.1 8.1 7.9 7.8 7.6 8.3
µ·in/in °F 4.5 4.5 4.5 4.4 4.3 4.2 4.6
Compressive Strength
N/mm2 170 140 150 125 105 170 110
psi 25,000 20,000 22,000 18,000 15,000 25,000 15,500
Flexural Strength
N/mm2 110 85 90 70 55 95 60
psi 16,000 12,000 13,000 10,000 8,000 13,500 8,500
Tensile Strength (1)
N/mm2 75 60 60 50 38 65 40
psi 11,000 8,500 9,000 7,000 5.500 9,500 6,000
Hardness
SSH 85 74 80 72 68 91 65
Electrical Resistivity
µ·ohm·cm 1,950 1,500 2,000 1,650 1,900 2,800 1,220
µ·ohm·in 770 600 790 650 750 960 480
Apparent Density
g/cc 1.80 1.77 1.77 1.73 1.65 1.77 1.82
lb/in3 0.065 0.064 0.064 0.063 0.06 0.064 0.066
Thermal Conductivity
watts/m K 72 95 85 85 76 60 105
BTU·ft/hr·ft2·° F 42 55 50 50 44 35 60
Oxidation Threshold (2)
°C 450 440 450 430 420 480 460
°F 840 820 840 810 790 900 860

(1) Estimated at 70% of flexural strength.
(2) Temperature that results in 1% weight loss in 24 hours. Oxidation threshold increases by approximately 100º C if graphite is purified. Exludes copper impregnated material.