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, Нержавеющая сталь марки 304 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
| Фактор | 201 Stainless Steel | Нержавеющая сталь 304 |
|---|---|---|
| Stainless Steel Type | Austenitic stainless steel | Austenitic stainless steel |
| Содержание никеля | Нижний | Выше |
| Manganese Content | Выше | Нижний |
| Устойчивость к коррозии | Moderate; suitable for mild environments | Excellent; better suited to humid and corrosive environments |
| Прочность | Generally higher yield strength | Generally lower yield strength but better overall ductility |
| Formability | Хорошо | Превосходно |
| Свариваемость | Хорошо | Превосходно |
| Обрабатываемость | Good, but work hardening can affect cutting performance | Good, with work hardening requiring proper cutting parameters |
| Отделка поверхности | Хорошо | Excellent and widely used for decorative finishes |
| Стоимость материала | Нижний | Выше |
| Типовые применения | 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?
201 vs 304 Stainless Steel Composition
| Элемент | 201 (%) | 304 (%) |
|---|---|---|
| Хром | 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 никель content result in poor toughness. This makes it more prone to brittle fracture under low-temperature or impact loads.
- Сайт 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
201 vs 304 Machining and Fabrication
| Процесс | 201 | 304 |
|---|---|---|
| Обработка на станках с ЧПУ | Harder, so it needs aggressive machining parameters | Machines more predictable |
| Сварка | Good, but more prone to hot cracking | Очень хорошо |
| 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.
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.
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 отверстия, threadings, thin walls or reworked finishes require stricter control and careful tool handling, thus decreasing the initial advantage of using cheaper materials.
201 vs 304 Stainless Steel: How to Identify Each 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.
- РФА тестирование: An XRF machine gives a precise chemical readout in seconds, which helps determine the steel grade type.
Заключение
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?
На сайте FS Fab, Мы предоставляем индивидуальная обработка с ЧПУ 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.
По ссылке Рафик
По ссылке Исурика
По ссылке Стивен Мусау
Пока нет комментариев, добавьте свой голос ниже!