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Physical & Electrical Properties |
Isolantite Manufacturing Company, Inc. manufactures steatite in two grades to meet the needs of varying applications. To assist the electrical engineers in making a decision as to the electrical and mechanical suitability of Isolantite insulators, these characteristics are presented. Questions relating to the nature or meaning of this data can be discussed with our engineering department so that a suitable and economic selection can be made. For most standoff and suspension applications, Grade L-5 steatite is supplied as standard. Strain insulators and low voltage consumer components are usually Grade L-4 steatite.
| Physical & Electrical Characteristics (Average Values) |
Unit |
Steatite No. 451 (L-4) |
Steatite No. 350 (L-5) |
| Water Absorption |
â |
0 to .05 |
Nil |
| Specific Gravity |
- - |
2.6 |
2.7 |
| Density |
lbs. per cu. in. |
0.094 |
0.097 |
| Hardness |
Mohs' scale |
7.5 |
7.5 |
| Linear Coeff. of Thermal Expansion |
per ƒC (40ƒ to 250ƒ) |
8.8 x 10-6 |
9.5 x 10-6 |
| Safe Continuous Use Temperature |
ƒC |
980 |
930 |
| ƒF |
1800 |
1700 |
| Tensile Strength |
psi |
10,000 |
9000 |
| Compressive Strength |
psi |
90,000 |
80,000 |
| Flexural Strength, 5" span |
psi |
22,000 |
21,000 |
| Thermal Conductivity (approximate) |
g.cal. x cm. thk./cm2. x sec. x ƒC |
0.006 |
0.006 |
| Dielectric Strength (Test disks 1/4" thick) |
v. per mil |
240 |
275 |
| Dielectric Constant 1.0 MHz (Wet Measurement) |
- - |
5.9 |
6.1 |
| Power Factor 1.0 MHz (Wet Measurement) |
- - |
0.002 |
0.0009 |
| Loss Factor 1.0 MHz (Wet Measurement) |
- - |
0.012 |
.005-.006 |
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