It is known that the density of ductile tungsten wire changes when the wire is drawn to smaller diameters but the results of several experiments do not agree as to the nature of the variation. Fink (Trans. Amer. Electro. Chem. Soc., 17, p. 229, 1910) gives data to show that the density increases with the drawing, the variation being 18.81 g/cm3 before drawing to 20.19 g/cm3 when drawn to a diameter of 0.038 mm. His method of measurement was not described. Doctor Sieg, in working with a number of tungsten wires, also found an increase of density with the drawing. In a letter to Doctor Sieg, Doctor Worthing of the Nela Research Laboratory, National Lamp Works of the General Electric Company, gave Doctor Lorenz's results on the variation of density with drawing. Doctor Lorenz used pyknometer and other ordinary specific gravity methods and found that the density decreases as tungsten is drawn finer and finer.
Proceedings of the Iowa Academy of Science
©1917 Iowa Academy of Science, Inc.
"Effect of Drawing on the Density and Specific Resistance of Tungsten,"
Proceedings of the Iowa Academy of Science, 24(1), 235-240.
Available at: https://scholarworks.uni.edu/pias/vol24/iss1/37