Stainless steel 304 and stainless steel 304L are also known as 1.4301 and 1.4307 respectively. 304 is the most versatile and widely used stainless steel. It is still sometimes referred to by its old name 18/8 which is derived from the nominal composition of 304 being 18% chromium and 8% nickel. 304 stainless steel is an austenitic grade that can be severely deep drawn. This property has resulted in 304 being the dominant grade used in applications like sinks and saucepans.
Stainless steel 304 and stainless steel 304L are also known as 1.4301 and 1.4307 respectively. 304 is the most versatile and widely used stainless steel. It is still sometimes referred to by its old name 18/8 which is derived from the nominal composition of 304 being 18% chromium and 8% nickel. 304 stainless steel is an austenitic grade that can be severely deep drawn. This property has resulted in 304 being the dominant grade used in applications like sinks and saucepans.
304L is the low carbon version of 304. It is used in heavy gauge components for improved weldability.
304H, a high carbon content variant, is also available for use at high temperatures.
|
|
C |
Si |
Mn |
P |
S |
Ni |
Cr |
Mo |
N |
|
SUS304 |
0.08 |
0.75 |
2.00 |
0.045 |
0.030 |
8.50-10.50 |
18.00-20.00 |
－ |
0.10 |
|
SUS304L |
0.030 |
1.00 |
2.00 |
0.045 |
0.030 |
9.00-13.00 |
18.00-20.00 |
－ |
－ |
|
304H |
0.030 |
0.75 |
2.00 |
0.045 |
0.030 |
8.00-10.50 |
18.00-20.00 |
- |
- |
|
Grade |
Tensile Strength (MPa) min |
Yield Strength 0.2% Proof (MPa) min |
Elongation (% in 50 mm) min |
Hardness |
||
|
|
|
|
|
Rockwell B (HR B) max |
Brinell (HB) max |
HV |
|
304 |
515 |
205 |
40 |
92 |
201 |
210 |
|
304L |
485 |
170 |
40 |
92 |
201 |
210 |
|
304H |
515 |
205 |
40 |
92 |
201 |
- |
304H also has a requirement for a grain size of ASTM No 7 or coarser.
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100 °C (J/kg.K) | Electrical Resistivity (nΩ.m) | |||
| 0-100 °C | 0-315 °C | 0-538 °C | at 100 °C | at 500 °C | |||||
| 304/L/H | 8000 | 193 | 17.2 | 17.8 | 18.4 | 16.2 | 21.5 | 500 | 720 |
| Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
| BS | En | No | Name | ||||
| 304 | S30400 | 304S31 | 58E | 1.4301 | X5CrNi18-10 | 2332 | SUS 304 |
| 304L | S30403 | 304S11 | - | 1.4306 | X2CrNi19-11 | 2352 | SUS 304L |
| 304H | S30409 | 304S51 | - | 1.4948 | X6CrNi18-11 | - | - |
| These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted. | |||||||
| Grade | Why it might be chosen instead of 304 |
| 301L | A higher work hardening rate grade is required for certain roll formed or stretch formed components. |
| 302HQ | Lower work hardening rate is needed for cold forging of screws, bolts and rivets. |
| 303 | Higher machinability needed, and the lower corrosion resistance, formability and weldability are acceptable. |
| 316 | Higher resistance to pitting and crevice corrosion is required, in chloride environments |
| 321 | Better resistance to temperatures of around 600-900 °C is needed…321 has higher hot strength. |
| 3CR12 | A lower cost is required, and the reduced corrosion resistance and resulting discolouration are acceptable. |
| 430 | A lower cost is required, and the reduced corrosion resistance and fabrication characteristics are acceptable. |
