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.