An Investigation of the Sinking and Mandrel Drawing Processes

Abstract

The experimental and theoretical investigation of the two tube drawing processes was undertaken with a view to achieving correlation between the approximate theories and drawing practice. Such correlation would, in effect, make possible the estimation of the importance and magnitude of various parameters, especially when drawing conditions are altered, without the necessity of carrying out experimental tests in tube mills. The theoretical basis for the present work is provided by the Baldwin and Sachs theory of sinking and the Sachs theory of mandrel drawing. The experimental investigations were based on 0·10 per cent carbon steel. The methods of obtaining true mean yield stress and coefficient of friction are discussed. Drawing stresses and other parameters are determined, and it is shown that, in both cases, the agreement between the measured and calculated values is good and that therefore the use of the approximate mathematical expressions is justified. The components of the total work done in drawing tubes by either of the techniques are discussed and further evidence is obtained for the statement that the amount of redundant work in tube drawing depends on the amount of sink present in the operation.