Alumina Tube 99.7%

No.	Property	Unit	Corundum Grade
1	Al₂O₃ Content	%	99.3
2	SiO₂ Content	%	–
3	Density	g/cm³	3.88
4	Water Absorption	%	0.01
5	Compressive Strength (Room Temperature)	MPa	350
6	Hardness	—	Mohs Hardness 9; Rockwell Hardness 85–90
7	Leak Rate at 20°C	Torr/(L·s)	<10⁻¹¹
8	High-Temperature Deflection	mm	0.2 allowable at 1600°C
9	High-Temperature Bonding	—	Non-sticking (no bonding) at 1600°C
10	Coefficient of Thermal Expansion (20–1000°C)	×10⁻⁶/°C	8.2
11	Thermal Conductivity	W/(m·K)	25
12	Dielectric (Insulation) Strength	kV/mm	20
13	DC Insulation Resistance at 20°C	Ω/cm	10¹⁴
14	High-Temperature Insulation Resistance	MΩ	≥0.08 at 1000°C; ≥0.02 at 1300°C
15	Thermal Shock Resistance	—	No cracking after 4 cycles from 1550°C
16	Maximum Service Temperature	°C	1800

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