What is the difference between SUS301 and SUS304?
SUS304 (stainless steel):
This is the most commonly used type of stainless steel. Due to its nickel content, it has better corrosion resistance and heat resistance than chrome steel.
It also has good mechanical properties and a high hardening rate, making it ideal for use in structural supports that require resistance.
SUS304 is non-magnetic and has good resistance, but is less elastic. It is typically used in thicknesses between 0.4T to 1.0T. When used in notebook applications, it is important to specify the appropriate class to meet the design requirements. The best option is usually 3/4H. For stretching and drawing applications such as LCD brackets, 1/2H is typically recommended.
However, some companies now use SUS430 instead of SUS304 to save money.
SUS301 (stainless steel):
This type of stainless steel has a lower chromium content than SUS304, which makes it less resistant to corrosion. However, it can achieve very high tensile strength and hardness through cold working, making it suitable for a wide range of applications.
Due to its elasticity, it is commonly used in notebook applications for EMI shielding and elastic contact parts. However, it is typically used in thicknesses between 0.4T and 0.07T, and it is important to specify the appropriate grade to meet design requirements (such as elasticity and strength).
It should be noted that the direction of the metal's crystal structure in material 301 affects its hardness and brittleness, with higher grades being harder and more brittle. If not handled properly during forming, it can cause cracks in the corners and side walls.
Material properties:
SUS301: Suitable for elastic applications, with high carbon content and hardness. It is not prone to elastic fatigue, but it has low ductility and is not easily removed.
SUS304: Not suitable for elastic, low carbon and low hardness (soft) applications. SUS430: Contains more impurities, resulting in unstable hardness.
Observation:
- If the hardness of both materials is similar, such as SUS301 3/4H and SUS304 H, although the hardness is the same, SUS304 H is more likely to suffer elastic fatigue when used in elastic products.
- The thickness of the material affects the hardness tolerance (the thicker the material, the higher the tolerance).
SUS301
Chemical composition of SUS301:
| Note | SUS301 | |
| Chemical composition (Weight%) |
(W) | ≤0.15 |
| (Mn) | ≤2.00 | |
| (Ni) | 6:00-8:00 | |
| (Si) | ≤1.00 | |
| (P) | ≤0.035 | |
| (S) | ≤0.030 | |
| (No.) | / | |
| (Cr) | 4pm-6pm | |
Observation:
Heat treatment specification: Solution treatment at 1010-1150℃ followed by rapid cooling.
Metallographic structure: The microstructure is characterized by austenite.
Delivery condition: Generally delivered in the heat-treated state, with the specific type of heat treatment specified in the contract. If not specified, it will be delivered untreated.
Mechanical properties of SUS301
| Note | SUS301 | ||
| Mechanical properties | Tensile strength | σb (MPa) | ≥520 |
| Yield resistance σs | (Mpa) | ≥205 | |
| Stretching δs | (%) | ≥40 | |
| Area reduction | ψ(％) | ≥60 | |
| Akv impact energy (J) |
/ | ||
| Impact resistance value α kv (J/ cm2 ) |
/ | ||
| Toughness | / | ||
| Blank sample size | / | ||
Hardness: ≤187HB; ≤90HRB; ≤200HVK
| Note | Mechanical properties | ||||
|---|---|---|---|---|---|
| SUS304 | ANN | 200 max. | 205 minutes | 520 minutes | 40 minutes |
| SUS304 | 1/2H | 250 minutes | 470 minutes | 780 minutes | 6 minutes |
| SUS304 | 3/4H | 310 minutes | 665 minutes | 930 minutes | 3 minutes |
| SUS304 | FC | 370 minutes | 880 minutes | 11:30 am | / |
| SUS301 | ANN | 200 max. | 205 minutes | 520 minutes | 40 minutes |
| SUS301 | 1/2H | 310 minutes | 510 minutes | 930 minutes | 40 minutes |
| SUS301 | 3/4H | 310 minutes | 745 minutes | 11:30 am | 5 minutes |
| SUS301 | FC | 430 minutes | 1030min | 1320 minutes | 3 minutes |
| SUS301 | EH | 490 minutes | 1275 minutes | 1570 minutes | / |
SUS 301 density
SUS 301 has a density of 7.93 g/cm³.
Hardness SUS301
| Material | Hardness mark | Hardness value |
| SUS301 | 1/4H | 250 ~ above 250 |
| SUS301 | 1/2H | 300 ~ above 310 |
| SUS301 | 3/4H | 360 ~ above 370 |
| SUS301 | H | 400~ above 430 |
| SUS301 | EH | Above 490 |
SUS304
“SUS” is a general term for Japanese steel grades. SUS304 is a Japanese JIS standard stainless steel, which corresponds to China's 0Cr18Ni9 and USA's 304.
Properties: It has good corrosion resistance, heat resistance, low temperature resistance and mechanical properties. It has good hot working properties such as stamping and bending, and does not harden during heat treatment. It's not magnetic.
Uses: Household utensils, cabinets, internal piping, water heaters, boilers, bathtubs, automotive parts, medical devices, building materials, chemicals, food industry, agriculture and ship components.
SUS304 Properties
| Note | SUS304 | ||
| Mechanical properties | Tensile strength | σb (MPa) | ≥520 |
| Yield strength | σs (MPa） | ≥205 | |
| Stretching | δ5 (％) | ≥40 | |
| Area reduction | ψ(％) | ≥60 | |
| Impactful energy | Akv (J) | / | |
| Impact resistance | Value/αkv (J/ cm2 ) |
/ | |
| Toughness | / | ||
| Blank sample size | / | ||
Hardness: ≤187HB; ≤90HRB; ≤200HV
SUS304 Density
SUS 304 has a density of 7.85 g/cm³.
SUS304 stainless steel composition
| Note | SUS304 | |
| Chemical composition (WT%) | (W) | ≤0.07 |
| (Mn) | ≤2.00 | |
| (Ni) | 8:00-11:00 | |
| (Si) | ≤1.00 | |
| (P) | ≤0.035 | |
| (S) | ≤0.030 | |
| (No.) | / | |
| (Cr) | 5pm-7pm | |
