[机]?直壁空心钻头
... 执行部件（机械的） power unit 直壁空心钻头 straight wall bit 直边锉 blunt file ...
直壁空心钻头
"When you get to the top of the wall there is a straight drop, a small flat bit and a slope bringing the ground back to the same level, " he said.
BBC: Hopetoun House: Man sues over bat walk 'ha-ha' fall
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。