| APPEARANCE |
Dark Gray to Black |
| SIZE |
7"x9"x9' or 7"x9"x8'6"
(other sizes by special order) |
| WEIGHT |
230 to 275 lbs. |
| SURFACE HARDNESS |
4,000 – 7,000 lbs. |
| DENSITY |
58 – 70 Lbs. per cubic foot |
| THERMAL EXPANSION |
0.0075% per ºF |
| MODULUS OF RUPTURE |
2,000 PSI |
| MODULUS OF ELASTICITY |
Greater than 180,000 PSI |
| COMPRESSION |
30,000 PSI |
| FLAMMABILITY |
No combustion after 20 seconds of impinging flame;
self extinguished after 120 seconds of impinging flame |
| SPIKE INSERTION |
4,000 lbs. |
| SPIKE LATERAL RESISTANCE |
2,000 lbs. |
| SPIKE WITHDRAWAL |
2,200 lbs. (cut spike) |
| SCREW SPIKE WITHDRAWAL |
4,000 lbs. |
| RESISTIVITY |
500+Mega-ohms @ 500 volts. |
