SUS301 Vs SUS304: A Comprehensive Material Comparison

SUS301 vs SUS304

SUS304 (Stainless Steel):

It is the most commonly used type of stainless steel. It contains Nickel, hence, it has better corrosion resistance and heat resistance than Chromium steel. It also has low temperature strength, excellent mechanical properties, and significant work hardening.

It doesn’t harden through heat treatment and is non-magnetic. It has good strength, less elasticity, and is commonly used in thickness between 0.4T~1.0T. Therefore, it is widely used in Notebook brackets that require structural strength. The specific grade must be specified to meet design requirements.

Generally, 3/4H is suitable. If drawing is required, and it is used for LCD brackets, 1/2H is generally suitable. However, to save costs, some companies are substituting SUS430 for SUS304.

SUS301 (Stainless Steel):

Its Chromium content is lower than SUS304, so its corrosion resistance is inferior. However, it can achieve very high tensile strength and hardness through cold working. Its good elasticity makes it widely used in Notebooks for EMI protection and as flexible contact parts.

But it is commonly used in thickness between 0.04T~0.07T. The specific grade must be specified to meet design requirements (such as elasticity, strength).

Also, note that SUS301 material has metal crystalline directionality, the higher the grade, the harder and more brittle it is. If not handled carefully during forming, it can easily cause cracks at corners and side walls.

Material Properties:

SUS301: Suitable for elastic applications, has high carbon content, high hardness, less prone to elastic fatigue, poor ductility, and is not easy to draw.

SUS304: Not suitable for elastic applications, has low carbon content, low hardness (soft).

SUS 430: This material contains numerous impurities (not pure), leading to unstable hardness.

Notes:

1. If the hardness of the two is close, such as (SUS 301 3/4H and SUS 304H), even though the hardness is the same, SUS 304H is more likely to produce elastic fatigue when used in elastic products.

2. Material thickness affects hardness tolerance (the thicker the material, the greater the tolerance).

SUS301

SUS301 Chemical Composition

Rang	Chemical composition（WT%）
Rang	C	Mn	Ni	Si	P	S	Nb	Cr
SUS301	≤0.15	≤2.00	6.00-8.00	≤1.00	≤0.035	≤0.030	/	16.00-18.00

Heat Treatment Specification: Solution treatment at 1010-1150°C, rapid cooling.

Metallographic Structure: The structural characteristic is austenitic.

Delivery Condition: Generally delivered in heat-treated condition, the type of heat treatment is specified in the contract; if not specified, it is delivered in the non-heat-treated condition.

Mechanical Properties of SUS301

Rang	Mechanical and Physical Properties
Rang	Tensile Strengthδ b（MPa）	Yield Strengthδs（MPa）	Elongation Rateδ5（%）	Cross-sectional Shrinkage Rate（%）	Impact Energy Akv（J）	Impact Toughness Value α kv（J/cm²）	Hardheid	Sample Blank Size
SUS301	≥520	≥205	≥40	≥60	/	/	/	/

Hardness：≤187HB; ≤90HR；≤200HVK

Rang	Standard Mechanical Performance in Different States
Rang	Status Marker	Vickers Hardness HV	Yield Strength（YS）	Tensile Strength（TS）	Elongation Rate（EL）
SUS304	ANN	200max	205min	520min	40min
SUS304	1/2H	250min	470min	780min	6min
SUS304	3/4H	310min	665min	930min	3min
SUS304	FH	370min	880min	1130min
SUS301	ANN	200max	205min	520min	40min
SUS301	1/2H	310min	510min	930min	40min
SUS301	3/4H	310min	745min	1130min	Smin
SUS301	FH	430min	1030min	1320min	3min
SUS301	EH	490min	1275min	1570min

SUS301 Density

7.93g/cm³

Hardness of SUS301

Materiaal	Hardheidssymbool	Hardness Value
SUS301	1/4H	250 and above
SUS301	1/2H	300 to 310 and above
SUS301	3/4H	360 to 370 and above
SUS301	H	400 to 430 and above
SUS301	EH	Above 490

SUS304

SUS is a general term for Japanese steel grades.

SUS304 is a Japanese JIS standard stainless steel, corresponding to China’s 0Cr18Ni9, and America’s 304.

Characteristics: It has good corrosion resistance, heat resistance, low temperature strength and mechanical properties, good thermal processing such as stamping and bending, no heat treatment hardening phenomenon, and is non-magnetic.

Applications: Household items, kitchen cabinets, indoor pipelines, water heaters, boilers, bathtubs, auto parts, medical equipment, building materials, chemicals, food industry, agriculture, ship parts.

SUS304 Properties

SUS304 Stainless Steel Properties

Rang	Mechanical and Physical Properties
Rang	Tensile Strengthδ b（MPa）	Yield Strengthδs（MPa）	Elongation Rateδ5（%）	Cross-sectional Shrinkage Rate（%）	Impact Energy Akv（J）	Impact Toughness Value α kv（J/cm2）	Hardheid	Sample Blank Size
SUS301	≥520	≥205	≥40	≥60	/	/	/	/

Hardness：≤187HB; ≤90HR；≤200HVK

SUS304 Density

7.85g/cm^-3

SUS304 Composition

SUS304 Stainless Steel Composition

Rang	Chemical composition（WT%）
Rang	C	Mn	Ni	Si	P	S	Nb	Cr
SUS304	≤0.07	≤2.00	8.00~11.00	≤1.00	≤0.035	≤0.030	/	7.00~19.00
SUS301	≤0.15	≤2.00	6.00~8.00	≤1.00	≤0.035	≤0.030	/	6.00~18.00