Mild steel
AKA: A36 / Q235 class
EconomicalPowder / black oxideEasy to machine
Economical structural steel; powder / black oxide / zinc common.
Material family
Steel
Mild to alloy and tool steels — tooling, shafts, wear duty.
4 quote-ready grades
1045 carbon steel
AKA: 1045 / C45
Medium carbonShaftsHeat-treatable
Medium-carbon steel; stronger than mild steel — common for shafts.
4140 alloy steel
AKA: 4140 / 42CrMo class
High strengthTough / impactConfirm heat treat
Alloy structural steel; confirm heat treatment with engineering.
Tool steel (general)
AKA: general tool-steel class
Wear resistantTooling classSpecify grade in notes
Wear/tooling class — specify exact grade in notes (SKD / S136 etc. via engineer).