While many laboratory studies of the "stainless" properties were performed between 1904 and1920，it was not until almost half a century later that stainless steels were produced on agenuinely industrial scale. Apart from early difficulties in controlling the composition,particularly the carbon content，the extraordinary development that was to come was due largelyto the increased availability of the constituent，i.e. chromium，nickel，molybdenum andmanganese (which can be used as a substitute for nickel). Furthermore，for stainless steel to becompetitive，these elements had to be available at a reasonably low cost.