pillar bolt 中文意思是什麼
pillar bolt
解釋
支撐螺栓-
Discussion on small pillar support roadway bolt support
小煤柱護巷錨桿支護探討 -
Bolt with bar and wire mesh cable supporting in driving gob - side entry along water - immersed pillar
水浸煤柱沿空掘巷的錨梁網索支護
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