A shop-floor identification technique where a piece of steel is pressed against a high-speed grinding wheel. The operator observes the color, shape, length, and branching pattern of the resulting spark stream to estimate the carbon content and identify alloying elements like tungsten or molybdenum.
Heard on the job
Do a quick spark test on that bar stock to make sure it's high carbon before we forge it.
Insider tip
High carbon steels produce short, bushy sparks with many bursts, while low carbon steels throw long, straight, yellowish shafts.
Also heard as
- spark testing