You will need
  • Chisel, hammer; grindstone
Method the first. Remove products shavings with a chisel. If you are dealing with high carbon steel, the chips will be short and brittle. Products made of low carbon steel to give long and plastic shavings. This way you can roughly get an idea about the content in carbon steel.
The second way. Will nodelete steel product before and after hardening with a file. If the steel after quenching sawed as easily as before, it is mild. If, however, after quenching the steel product has become more difficult to process a file, the steel is practically useless for hand-forged of high carbon content.
The third method is based on the visual analysis of sparks from the grinding wheel. Sparks are the smallest particle of hot iron. The more sparks and the bigger they are, the harder the metal.Press the product to the rotating abrasive circle. Place the metal sample so that the sparks are perpendicular to the line of vision. During the test, press the sample evenly, this will depend on the length of the spark; pressing with different strength, can give a distorted result. Near the grinding wheel, install a sheet of black plywood – so the sparks will be seen better.
In the analysis, consider the following parameters: the length of the sparks, the character of the sparks, their number (the width of the sheaf), the presence of stars, the colour of sparks, the brightness of the glow. Short and wide beam of sparks is reddish with a large number of stars indicates a high carbon steel. Steel with medium carbon content has a bright shower of sparks with little stars. Ornamental for low carbon steel indicate a long, continuous, slightly curved spark yellow straw color without the asterisks with two bulges at the end and in the middle.
Use to determine the quality of steel special tables, allowing to define the brand in color and form sparks. It is recommended to have in a workshop a set of samples of different grades of steel with vignettes, which will help to compare the spark when determining the grade of steel.