Evaluation and Repair of Wrought Iron and - Purdue e-Pubs ...

18plot of this percent elongation data, of which the average percent elongation was found tobe 19.12% with a standard deviation of 6%. This standard deviation was 32% of theaverage found. Therefore, there was a large amount of variability in percent elongation ofthe wrought iron that Kirkaldy tested.While Kirkaldy was testing iron in England, Knut Styffe a Swedish scientist wastesting iron and steel that was manufactured in Sweden. His book Elasticity,Extensilbility, and Tensile Strength of Iron and Steel (1869) reported tensile strengths, orbreaking weights, of the puddled iron that he tested. Due to the condition of the Styffe’sbook, some of Styffe’s data is included in the combined tensile strength data collected forall historical testing results found, and can be seen in Figure 2.13. On a whole, the tensilestrength of Swedish wrought iron was considerably higher than the values found from thetesting in England.The majority of the materials testing completed during the nineteenth centurycame from Europe. Since the iron ore and manufacturing processes were slightlydifferent in the United States than in Europe, it was necessary to test material that wasproduced in the U.S. In 1875, President U. S. Grant of the United States appointed aboard to:“…determine, by actual tests, the strength and value of all kinds of iron, steel, andother metals which may be submitted to them or by them procured, and to preparetables which will exhibit the strength and value of said materials for constructionand mechanical purposes, and to provide for the building of a suitable machine forestablishing such tests, the machine to be set up and maintained at the Watertownarsenal.(Report of the United States Board, 1881)”The board researched and tested several subjects which included the “examination andreport upon the mechanical and physical properties of wrought iron.” Commander L. A.Beardslee U.S.N. was the chairman in charge of the committee that completed the testingof wrought iron. The majority of the material tested was round bar material that could beforged into chain link. This material could also be used as tension rods in bridges.