half-round drill 半圆钻 ; 勺钻
unthreaded round drill 无螺纹钻头
round drill rod 圆形钻杆
round drill 半圆钻 ; 球钻
round-shot drill 弹丸钻井
drill l round 炮眼组
half round drill 半圆钻
European peasants would insert a wooden drill in a round hole and rotate it briskly between their palms.
欧洲的农夫将一个木钻子放入一个圆孔并用手掌不停旋转它。
The army engineers paraded round drill squares.
工兵绕训练场列队行进。
Common round steel or steel tube may be rolled into solid or hollow twist drill rods by using the said rolling mill.
普通元钢或普通钢管经此轧机后,可直接变成实心或空心麻花钻杆钢。
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