904L vs. 304L Stainless Steel: Key Differences
Apr 24, 2026
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What is the difference between 304L and 904L stainless steel?
304L is an economical, general-purpose, low-carbon stainless steel suitable for welding; conversely, 904L is a high-alloy, super-austenitic stainless steel that offers exceptional corrosion resistance particularly against acids and features a composition containing copper, molybdenum, and a high nickel content. 904L is significantly more expensive and is primarily utilized in harsh environments, whereas 304L is suitable for general, mildly corrosive applications.
What type of stainless steel is 904L?
904L is a high-alloy, non-magnetic austenitic stainless steel (UNS N08904) that possesses exceptional corrosion resistance and is acclaimed as a "super-austenitic stainless steel." Characterized by a low carbon content, it is rich in nickel (23–28%) and chromium (19–23%), with substantial additions of molybdenum (4–5%) and copper; it is highly amenable to high-gloss polishing and is frequently utilized in chemical processing applications as well as in the manufacturing of high-end timepieces.
What does the L mean in 304L stainless steel?
304L stainless steel is a low-carbon austenitic alloy widely utilized for its exceptional corrosion resistance, excellent weldability, and broad processing adaptability. With its carbon content controlled below 0.03%, this alloy effectively prevents the precipitation of harmful carbides during welding, making it suitable for manufacturing "as-welded" thick-walled components in the food processing, chemical, and pharmaceutical industries.
904L vs. 304L Stainless Steel: Chemical Composition Comparison (%)
| Element | 304L (UNS S30403) | 904L (UNS N08904) |
| Chromium (Cr) | 17.5 – 19.5 | 19.0 – 23.0 |
| Nickel (Ni) | 8.0 – 12.0 | 23.0 – 28.0 |
| Molybdenum (Mo) | - | 4.0 – 5.0 |
| Copper (Cu) | - | 1.0 – 2.0 |
| Carbon (C) | ≤ 0.030 | ≤ 0.020 |
| Manganese (Mn) | ≤ 2.0 | ≤ 2.0 |
| Nitrogen (N) | ≤ 0.10 | ≤ 0.10 |
904L vs. 304L Stainless Steel: Mechanical & Physical
| Property | 304L Stainless Steel | 904L Stainless Steel |
| Tensile Strength (min) | 485 MPa (70 ksi) | 490 MPa (71 ksi) |
| Yield Strength (min) | 170 MPa (25 ksi) | 220 MPa (31 ksi) |
| Elongation (min) | 40% | 35% |
| Hardness (max) | 92 HRB | 90 HRB |
| PREN Value (Pitting) | ~18.0 | ~35.0 (Super-Austenitic range) |
| Density | 7.93 g/cm³ | 7.95 g/cm³ |
904L vs. 304L Stainless Steel: Corrosion Resistance
904L stainless steel offers superior corrosion resistance compared to 304L, particularly in harsh, acidic, and high-chloride (seawater) environments, due to its significantly higher nickel (23–28%), molybdenum (4–5%), and copper content. While 304L is an excellent, cost-effective, general-purpose alloy, it is prone to pitting in warm, salty conditions where 904L thrives.
904L vs. 304L Stainless Steel: Applications
Select 304L if your field involves food processing, clean water treatment, or general structural components. Select 904L if the media you are handling includes sulfuric acid, high-temperature seawater, or chemical washing systems-specifically in cases where the failure of 304L material would result in catastrophic environmental or economic losses.
904L vs. 304L Stainless Steel: Cost
The price of 904L stainless steel is significantly higher than that of 304L typically ranging from three to four times the cost a disparity primarily attributed to its elevated nickel (23%–28%) and molybdenum (4%–5%) content. As of the end of 2025, the price of 904L stood between $6.00 and $12.00 per kilogram; in contrast, the price of 304L was considerably lower, averaging approximately $1.50 to $3.45 per kilogram. Consequently, 904L has emerged as the preferred high-end material for applications within highly corrosive environments.
GNEE is a professional supplier and exporter of ASTM A213 TP304L and TP904L seamless tubes, specializing in the supply of both welded and seamless stainless steel tubing. All A213 tubes are manufactured using a seamless process and are either hot-finished or cold-finished in accordance with the specified requirements. Heat treatment is to be performed separately, or concurrently with the heating required for hot forming. All austenitic stainless steel tubes shall be supplied in the heat-treated condition, and the heat treatment shall be conducted in strict compliance with the requirements of the A213 standard.
ASTM A213 TP304L & TP904L Seamless Tubes specification
| Product Form | Size Range (OD x WT) | Common Lengths | Manufacturing Process & Applications |
| Straight Tubes |
OD: 6.35mm - 114.3mm WT: 0.5mm - 12.7mm |
6m, 12m, or custom lengths up to 18m | The basic form used for various types of heat exchangers, pressure vessels, and condensers. |
| U-Bent Tubes | Customized bending radius (R) based on heat exchanger tube sheets | Developed (unfolded) length up to 24m | A core component of heat exchangers. TP904L U-bent tubes are typically used in strong acid environments; TP304L is used for standard water/steam cycles. |
| Coiled Tubes |
OD: 3.18mm - 25.4mm WT: 0.5mm - 2.11mm |
Continuous long tubes ranging from hundreds to thousands of meters | Used for hydraulic control lines, chemical injection lines, or laboratory instrumentation tubing. |
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