Overview:
T304 Steel also known as 304 Steel is one of grade from the family of 300 Steel grades (301, 302, 303, 304, 307, 316, etc). The T304 steel is the one of the most soft grades. The difference which makes more recognizable as soft steel is that, this grade soft yet very durable, flexible and easy to trim, mold or bend.
T-304 is the most commonly used stainless all around the world. It is used in variety of products including forks, knives, steel wires, medical and personal care instruments, automobiles, machine parts, etc. It is weldable, machinable as well as has good corrosion resistance characteristics. Though it is good corrosion resistant but it is not recommendable for salt water environments. This material is hardenable by cold work, but mildly hardenable.
Grade T304 steel has a competitor known as T409. This steel grade is a low price grade compare to T304, therefore, at some places it is preferred than T304, but when it comes to reliability for long time, better finish and durability, T304 is the final choice. The T409 can get surface corrosion easily, though the corrosion appears on the surface does not damage the structure from inside and it is just on the surface. However, it is a huge negative point. Whereas, the T304 is more durable, has better surface finish and will not get surface corrosion unless it is exposed to really extreme atmosphere, such as Sea water, etc. Therefore, T304 is definitely a preferable choice than T409.
Grade type 304 is produced in various carbon levels i.e. T304 & T304L are low carbon grades and T304H is high carbon grade
T304 related specifications are: AISI 304/304L, ASTM A240 and AMS 5513/5511
Chemical Composition
Ingredients | Min. | Max. |
Iron (Fe) | 66.5 | 74% |
Carbon (C) | – | 0.08% |
Chrome (Cr) | 18 | 20% |
Manganese (Mn) | – | 2% |
Nickel (Ni) | 8 | 10.5% |
Phosphorus (P) | – | 0.045% |
Sulphur (S) | – | 0.03% |
Silicon (Si) | – | 1% |
Physical Properties
Grade | Tensile Strength Avg. | Yield Strength Avg. | Elongation | Rockwell Hardness |
T304 | 74,000 psi | 32,000 psi | 70% | B70 |