| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Helical steel support | Mining | A continuous screw-shaped steel joist lining for staple shafts. The lining is fixed to the ground by strata bolts rigidly fixed every 120 degrees without any yielding device. Developed in Germany and its use is claimed to effect considerable overall savings. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
