DEVELOPMENT OF ON-LINE WALL THICKNESS GAGE FOR SEAMLESS STEEL TUBES.

An on-line wall thickness gage was successfully developed for the first time in the world and introduced in the medium diameter seamless tube mill of Kawasaki Steel's Chita Works. The gage is of the multibeam type utilizing gamma -rays and capable of measuring the tube wall thickness to an accuracy of 0. 1 mm with no physical contact with the tube and by continuously scanning multiple points on the circumference of the tube over its entire length while it is still hot.