304 full hard stainless steel belongs to the austenitic family and is known for its excellent corrosion resistance and high strength. This grade is most commonly used in industries. It has a significant amount of chromium, at about 18 to 20 percent by weight, and a high amount of nickel, between 8 and 10.5 percent by weight.
All the 300 series alloys are most widely used due to their excellent properties, while 304 stainless steel alloys play a significant role among them. This alloy is non-magnetic in the annealed condition, but after cold working, it becomes magnetic. This grade of stainless steel can easily be welded and is primarily used in deep-drawn applications and the wire industry due to its excellent ductility.
304 full hard stainless steel has a lovely appearance, is simple to build, and is easy to clean. Additionally, it has low-temperature properties that can be hardened by cold working.
Chemical composition
Chemical composition of 304 full hard stainless steel
| Elements | Min | Max |
| Carbon | 0.08% | 0.08% |
| Manganese | 2.0% | 2.0% |
| Silicon | 1.0% | 1.0% |
| Chromium | 18.00% | 20.00% |
| Nickel | 8.00% | 10.5% |
| Phosphorus | 0.045% | 0.045% |
| Sulfur | 0.030% | 0.030% |
| Nitrogen | 0.10% | 0.10% |
| Iron | 66.3% | 74% |
Mechanical properties
The following table shows the mechanical properties of 304 full hard stainless steel.
| Tensile strength | Yield strength | Elongation | Hardness Vickers |
| 1130 MPa | 880 MPa | 0-3% | 370 HV Min. |
Application of 304 full hard stainless steel
This grade of stainless steel is generally used in the following applications:
- Bellows, chemical equipment,
- Coal dispenser linings, heat exchangers
- Evaporators, flatware utensils, feed water tubing, flexible metal hose
- Cooling coils and cryogenic vessels
- Dairy and cooking equipment
- Hospital surgical equipment,
- Hypodermic needles, kitchen sinks,
- Nuclear vessels, oil well filter screens,
- Marine equipment and fasteners
Stainless steel standards and chemical composition comparison table
Steel Grade | Chemical Composition | ||||||||||
| JIS | ASTM | EN/DIN | C (%) | Si (%) | Mn (%) | P (%) | S (%) | Ni (%) | Cr (%) | N (%) | P (%) |
| SUS304 | S30400/304 | 1.4301 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 8.0-10.50 | 18.00-20.00 | JIS SUS304 | |
| ≤0.07 | ≤0.75 | ≤2.00 | ≤0.045 | ≤0.03 | 8.0-10.5 | 17.50-19.50 | ≤0.10 | ASTM A240 | |||
| ≤0.07 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.015 | 8.0-10.50 | 17.00-19.50 | ≤0.11 | EN10088-1 | |||
There are three most commonly used standards for cold rolled stainless steel ASTM, JIS and EN/DIN. ASTM is an American standard, JIS standard for Japanese industrial standard and EN/ DIN standard is a European standard for stainless steel.
All of our 304 full hard stainless steel strips are fully compliant with all these international standards.
Surface finish
The surface finish of 304 stainless steel is known as the visual appearance of the metal. We can achieve a surface finish by polishing, rolling, and blasting. These finishes range from dull to shining; some have unique textures that can be physically applied for highly specialized purposes.
The surface finish of stainless steel plays a vital role in the applications where we use it. Through cold rolling and tempering, our 304 full hard alloys can be achieved in a surface finish of 2H/TR ( tempered rolled). It is a cold-worked, bright surface.
Surface roughness
Finished surfaces have many industrial uses but some application demand surface roughness. A surface’s average heights and depths are used to calculate surface roughness. When evaluating whether equipment complies with different industry standards, this parameter is most frequently represented as “Ra” for “Roughness Average.”
The surface roughness “Ra” of our 304 full hard stainless steel ranges from 0.1 to 0.3 micrometers.
Surface roughness standard and equivalents chart
| Number of Grades | Ra (Micrometers) | Ra (Micro inches) | Rt (Micrometers) |
| N1 | 0.025 | 1 | 0.3 |
| N2 | 0.05 | 2 | 0.5 |
| N3 | 0.1 | 4 | 0.8 |
| N4 | 0.2 | 8 | 1.2 |
| N5 | 0.4 | 16 | 2.0 |
| N6 | 0.8 | 32 | 4.0 |
| N7 | 1.6 | 63 | 8.0 |
| N8 | 3.2 | 125 | 13 |
| N9 | 6.3 | 250 | 25 |
| N10 | 12.5 | 500 | 50 |
| N11 | 25 | 1000 | 100 |
| N12 | 50 | 2000 | 200 |
Edge Finish
Handing the material without proper deburring is very harmful. We use proper edge-finishing methods when we cut or shear the stainless steel sheets or strips.
Deburred edges
Deburring edges remove the burrs, or tiny defects, from the machined surface of stainless steel.
Round edges
Our 304 full hard strips with round edges are most frequently used. The smooth surface of the stainless steel with rounded edges is free of defects and burrs.
Conclusion
304 full hard stainless steel is a significant grade of the austenitic stainless steel family due to its outstanding properties. We have expertise in making quality products of this grade of stainless steel.
