The four main high-carbon steel categories are explained below.
Alloyed: Other elements, like chromium, cobalt, manganese, molybdenum, nickel, tungsten, and/or vanadium, are sometimes added to steel to improve its hardness, strength, toughness, heat- and corrosion resistance. These extra ingredients will also raise the material’s price, so it’s typically only done when absolutely necessary. A common example of an alloyed high-carbon steel is stainless steel.
Spring steel: This type has a carbon content of 0.6–1.0%, and it sometimes has varying amounts of other alloying elements. Most importantly, spring steel has silicon which gives it a high yield strength, and makes it flexible—hence the bouncy name.
Plain carbon steel: As the Plain Jane of steel, this type doesn’t have any other alloying elements (well, none of significance, anyway). It’s hard to weld, fails after minimal elongation, and is sensitive to heat treatments, but, on the bright side, it is the cheapest form of high-carbon steel.
Tool steel: Alloyed with tungsten, molybdenum, cobalt, and vanadium, tool steel is extra durable—which is just as well since it’s used to make tools—and it has excellent heat resistance so won’t temper in high temperatures.
