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

简要地介绍了三机所毛管的质量及该机特有的轧制故障预防措施。

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

对设而言,指无马达用手操作的设(工键机、工打字机)。

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

机是轧制钢管的重要设,而机架又是机的核心组成部分。