taper of groove

In this system,owing to the fact that vertical pass has the character of big groove bottom,little angle of side and short groove life,it often occurs slanting and torsion in pre-splitting which easily brings about production accident.

在这一系统中,由于立箱孔槽底大,侧壁斜度小,所以轧槽寿命短,预切孔切分时常切偏和扭转,生产事故较多。