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