201 VS 304 Stainless Steel: Which Is Right For Your Part?

FS Fab Blog

201 and 304 are two common grades of stainless steel. Their main difference lies in their chemical composition, which affects corrosion resistance, strength, and machinability. 201 stainless steel is frequently used in applications where cost is a priority and corrosion resistance is not a top concern. On the other hand, 304 stainless steel is often chosen for applications that demand high corrosion resistance, food safety, and durability.

In this article, we will cover each grade’s composition, properties, and cost differences. You will also discover ways to distinguish 304 from 201 and how to make a wise decision between them.

201 vs 304 Stainless Steel at a Glance

Factor	201 Stainless Steel	304 Stainless Steel
Stainless Steel Type	Austenitic stainless steel	Austenitic stainless steel
Nickel Content	Lower	Higher
Manganese Content	Higher	Lower
Corrosion Resistance	Moderate; suitable for mild environments	Excellent; better suited to humid and corrosive environments
Strength	Generally higher yield strength	Generally lower yield strength but better overall ductility
Formability	Good	Excellent
Weldability	Good	Excellent
Machinability	Good, but work hardening can affect cutting performance	Good, with work hardening requiring proper cutting parameters
Surface Finish	Good	Excellent and widely used for decorative finishes
Material Cost	Lower	Higher
Typical Applications	Indoor equipment, decorative parts, furniture, appliances, brackets	Food equipment, outdoor parts, industrial components, enclosures, architectural and medical applications
Best Fit	Cost-sensitive parts in relatively mild environments	Parts requiring higher corrosion resistance and long-term durability

What Is the Difference Between 201 and 304 Stainless Steel?

Both 304 and 201 are austenitic steels that share a similar surface appearance. What makes them differ is composition, which overly effects the cost, performance, and application of each grade as follows.

201 vs 304 Stainless Steel Composition

304 and 201 steels have similar alloying elements, but at varying amounts as shown in the table below:

Element	201 (%)	304 (%)
Chromium	16.0 – 18.0	18.0 – 20.0
Nickel	3.5 – 5.5	8.0 – 10.5
Manganese	5.5 – 7.5	2.0 max
Nitrogen	0.25 max	0.10 max
Carbon	0.15 max	0.08 max
Silicon	1.00 max	0.75 max

201 vs 304 Mechanical and Physical Properties

Yield strength: Thanks to its high-manganese, high-nitrogen composition, the yield strength of 201 is higher than that of 304. In the annealed state, 201 is slightly “harder.”
Elongation: 304 has an elongation of at least 40% and excellent formability, making it suitable for complex forming processes, such as bending and stretching. Although 201 has relatively high elongation (55–60%), its high manganese and low nickel content result in poor toughness. This makes it more prone to brittle fracture under low-temperature or impact loads.
The modulus of elasticity: It reflects a material’s stiffness, or resistance to deformation. For the same cross-sectional dimensions, the resistance to deformation of both grades is essentially equivalent.

Corrosion Resistance: Why 304 Stands Out

304’s passive chromium oxide film is more stable and more durable because of the higher nickel content, which reinforces the film’s structure at the atomic level. So, in humid, outdoor, and acidic conditions, 304 resists rust more reliably.

In contrast, 201 has less nickel content, which makes it more susceptible to corrosion. This is because of the thinner passive film, which breaks down easily to initiate pitting corrosion.

201 vs 304 Machining and Fabrication

201 steel is harder than 304 steel due to its higher manganese content, making it more difficult to machine. This means that at light feeds or shallow cuts, the work surface hardens ahead of the tool and causes tool wear.

Considering other operations such as welding, bending, and forming, 304 and 201 compare as shown in the table below:

Process	201	304
CNC machining	Harder, so it needs aggressive machining parameters	Machines more predictable
Welding	Good, but more prone to hot cracking	Very good
Forming and bending	Good formability, but work-hardens faster during cold working	Very good formability and lower work-hardening rate
Anodizing/passivation	Highly requires passivation to improve resistance to rusting	Standard passivation for food and medical applications

How to Choose Between 201 and 304 for Your Part

Both 201 and 304 stainless steel can be CNC machined, but the optimal choice varies significantly based on part geometry and machining requirements.

For relatively simple parts where material cost is important and corrosion exposure is limited, 201 stainless steel is a practical choice. However, if a part has a complex design, requires high corrosion resistance and durability, or has strict aesthetic requirements, 304 stainless steel is the better choice.

Here are some key principles for deciding:

Corrosion resistance must be considered a critical criterion for selection, especially for CNC parts exposed to moisture, cleaning chemicals, or outdoor conditions.

304 offers better corrosion resistance compared to 201 and hence makes a good choice for parts that operate in humid conditions, are often washed, subjected to condensation, or are operated in mildly corrosive mediums.

Food-contact requirements should be considered when making the choice of 304 over 201.

304 stainless steel is commonly used in food processing machinery and parts due to its corrosion-resistant properties and successful track record in these types of environments. Therefore, it is preferable to choose 304 stainless steel when designing a machined part that will come into direct contact with food.

For simple turned or milled parts, 201 can be a cost-effective option.

Components like brackets, spacers, shafts, sleeves, and other simple machine parts may not need the enhanced corrosion resistance offered by 304. When the geometry is relatively open and rigid, then 201 stainless steel could be machined using sharp tools.

When machining consistency matters, 304 is often the safer choice for parts with complex milling features.

Deep pockets, narrow slots, small steps, and repeated finishing passes can make work hardening more problematic. With 201, insufficient feed rate, excessive tool dwell time, or a dull cutting edge can harden the surface, increasing cutting forces and tool wear.

Therefore, when machining grade 201, the right machining approach is needed. For instance, keep feed and depth of cut aggressive enough to stay below the work-hardened surface layer. Also, use sharp carbide tooling and swap tools before the edge dulls rather than after.

Surface finish can also influence the choice.

Both materials are capable of delivering excellent CNC finishes, but 304 is often used when the finished component is to be visible and brushed or polished. The finish of the 201 can change easily if there is not sufficient control of the condition of the cutting tool and the machining vibrations. If the part is to be used cosmetically, then it would be better to specify the necessary surface finish directly on the drawing.

Does 201 Really Save Money Compared with 304?

201 stainless steel is generally less expensive than 304 because it contains less nickel. In this sense, in the manufacturing of simple CNC parts that would be used in dry and mild environment, the cheaper material cost could provide an economic benefit.

However, a lower material price does not always mean a lower finished-part cost. Complex CNC parts that contain a number of holes, threadings, thin walls or reworked finishes require stricter control and careful tool handling, thus decreasing the initial advantage of using cheaper materials.

The service environment also matters. For example, if the 201 part is going to be used in a wet environment or will need constant cleaning, the low corrosion resistance of the material would lead to increased maintenance costs. In such cases, the higher cost of 304 stainless steel might be worth it for its enhanced corrosion resistance.

201 vs 304 Stainless Steel: How to Identify Each Grade

When material is not clearly marked, these methods help confirm the grade.

Mill certificates: Every order ships with an MTC showing alloy designation, heat number, and composition per ASTM A240.
Surface feel: 304 has better luster and a smoother feel. 201, on the other hand, tends to look duller and feel rougher. In addition, wet your hands and touch the two types of stainless steel sheets. You will find that the water marks and fingerprints on the 304 sheet are easier to wipe off than those on the 201 sheet.
Grinding spark test: Grind both 304 and 201 lightly with equal pressure. That way, 201 throws longer, thicker sparks. 304 throws shorter, thinner ones.
Pickling paste test: Apply pickling paste to both surfaces and wait two minutes. As a result, 201 will darken or blacken in the treated area while 304 will whiten or show no color change.
XRF testing: An XRF machine gives a precise chemical readout in seconds, which helps determine the steel grade type.

Conclusion

201 and 304 stainless steel can both be used for CNC machined parts, but they suit different manufacturing and service requirements. Although 201 stainless steel is typically less expensive than 304 stainless steel, it has poorer corrosion resistance. Therefore, 304 stainless steel is the better choice for use in humid environments and when food safety requirements must be met.

If the material selection is uncertain, it is more reliable to work from the actual part drawing and application requirements than to choose based on price alone.

Need help selecting 201 or 304 for your CNC parts?

At FS Fab, we provide custom CNC machining for stainless steel components, including prototypes, small batches, and production runs. Send us your drawings and specifications to receive material recommendations and a quote for CNC machining.

FAQs

Is 201 stainless steel magnetic?

201 is non-magnetic when annealed, just like 304. However, it can develop slight magnetism after bending or forming.

Will 201 stainless steel rust?

201 rusts more readily than 304, especially in humid and salty environments. This is due to the lower nickel content in 201, which produces a weaker passive film that is less resistant to rust.

Can 201 be welded like 304?

Yes, 201 can be welded. However, it is more prone to hot cracking, so it needs the correct filler like ER308L or ER309L. Also, the welding parameters and heat input must be managed carefully to minimize the risk.

Is 201 stainless steel food safe?

201 is acceptable for short-term or dry food contact in non-acidic conditions. But for food processing equipment, kitchen surfaces, or any contact with acidic foods or liquids, 304 is the standard specification as per the FDA and NSF guidelines.

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About the Author

Stephen Musau

Stephen is a content writer and editor with a strong background in Mining and Mineral Processing Engineering. He enjoys helping readers understand CNC machining, materials, and industrial processes in a clear and practical way. Stephen focuses on creating content that is accurate, well-researched, and easy to follow, making complex technical topics accessible to everyone.