This paper expounds an abnormal phenomenon occurring in the course of internal threading and the causes of it, makes detailed analysis on occurrence and calculating methods of the pitch, tooth-type half-angle, pitch diameter, etc.

Treatment on abnormal phenomena of magnesium content determination in phosphate rock;

Analysis of abnormal phenomena in ultimate bearing capacity of bored pile;

In the paper,we will analyze the abnormal phenomena appeared using in the determinator and introduce some knowledge and experience in service.