Mild Steel Sheet 101
Not every application calls for a high strength or an advanced high strength steel like 4130 chrome moly (chromoly) or Docol® and Strenx®. Sometimes you just need a mild steel.
Well … what is Mild Steel anyway?
Mild Steel is a low carbon steel or a steel containing a typical carbon amount of 0.05% to 0.25% by weight. Mild steel is not an alloyed steel which means that it is predominantly composed of iron and does not contain vast amounts of chromium, molybdenum or other alloying elements.
Mild Steel is produced by smelting iron ore in a blast furnace where carbon is added into the mixture and all other impurities are removed. Adjustments are also made at this point to produce the chemical composition needed to make mild steel. The steel is then allowed to cool into an ingot (slab). From there, the ingot is then reduced to its desired size by either a “Hot Rolling” or “Cold Rolling” process.
Mild steel sheet is produced in Hot Rolled, Hot Rolled Pickled and Oiled, and Cold Rolled conditions predominantly in 1008 and 1010 Grade carbon steel.
Hot Rolled Mild Steel Sheet
Hot Rolled refers to the process of reducing the ingot’s thickness at a high temperature above steel's recrystallization temp (minimum 1700 deg F), allowing the metal to be formed or shaped more easily. Hot Rolled steel is typically less expensive than Cold Rolled steel, because it can be finished much faster and to looser tolerances.
Hot Rolled Pickled and Oiled Mild Steel Sheet
Hot Rolled Pickled and Oiled, abbreviated as P&O or HRPO, is a further treatment to Hot Rolled sheets. The sheet is dipped in an acid-based solution to remove impurities (such as scale, inorganic contaminants, stains, etc.) from the surface. Oil is then applied to prevent rusting. This gives a typically cleaner surface finish than plain Hot Rolled sheets.
Cold Rolled Steel Sheet
Cold Rolled refers to the process of reducing a Hot Rolled thickness even farther, at room temperature when the metal is no longer pliable or plastic. Cold rolling results in an improved surface finish and tighter tolerances. Cold Rolled steel sheet is available in 24 Ga (.024") through 12 Ga (.104").