Of equipment; without a motor and intended for hand operation (“a manual keypunch”; “a manual typewriter”).

对设备而言,指无马达和用手操作的设备(如人工键穿孔机、人工打字机)。

The briefing covers quality of the shell pierced by the three-high piercing mill, thespecific rolling failures and countermeasures thereagainst.

简要地介绍穿孔机所穿毛管的质及该穿孔机特有的轧和预防措施。

Piercing mill is the most important equipment on the rolling pipe line,and the frame is the nucleal component of the piercing mill.

穿孔机是轧钢管的重要设备,而机架又是穿孔机的核心组成部分。