During the last blog, the preparation of the sample was discussed. It can be seen that while the test is not a quantitative test or a conclusive test, it is at least an indicative test of identification. What effect do the alloying elements have on the resulting spark of the sample?

• Carbon will cause a very bright and feathery spark just as one might see on a child’s sparkler. The more carbon present in the steel, the brighter and more plentiful are the bursts.
• Molybdenum will tend to diminish the sparks on the feathery bursts and will give off a yellow color. In the stainless steels, the chromium produces a much-diminished spark. In the tool-steel range, the molybdenum will produce a long-stream spark, which emerges almost as a spear point would be at the tip of the spark.
• Chromium will produce an orange spark. In the stainless steels, the chromium produces a much-diminished spark. In the tool-steel range, chromium will tend to make the spark long with small spark streams coming off the main spark.
• Tungsten will suppress the spark color to a darker orange to red color and also suppress the ability for the steel to make a spark, particularly with high-tungsten steels.
• Nickel will tend to make the spark long and clear until at the end of the spark stream when there is a slight burst.
• Manganese will brighten the spark and tends to make the spark go around the grinding wheel.

Please be aware that the spark test is anything but quantitative. It will give you an idea as to what the steel might be, but it is not a guarantee of the steel’s analysis. With your test kit of known steel samples, however, you can identify very closely what type of steel you are testing.