Specifications
- Plate, Sheet & Strip: ASTM A240
- ASTM B625
904L Stainless steel, or UNS N08904, is an advanced alloy widely sought after for its corrosion resistance in harsh environments. 904L stainless fasteners offer superior resistance to chloride stress-corrosion cracking, pitting and reducing acids compared to similar stainless steel alloys, such as 316L. These characteristics make them valuable in numerous industries such as chemical processing and pharmaceuticals.
At Nickel Systems, we stock a wide range of 904L Stainless fasteners to suit the needs of engineers, designers and purchasing managers from various sectors. Contact us today for fast delivery and premium quality products.
UNS N08904 portrays desirable physical, mechanical and corrosion-resistant properties that make it reliable in critical applications. If you fail to find the answers to your questions below, download the complete technical data sheet here.
| Density | lb/in3 | 0.287 |
|---|---|---|
| g/cm3 | 7.95 | |
| Specific Heat | Btu/lb•°F (32-212°F) | 0.11 |
| J/kg•°C (0-100°C) | 450 | |
| Electrical Resistivity | Microhm-in at 68°F | 33.5 |
| Microhm-cm at 20°C | 95.2 | |
| Modules of Elasticity | x 106 psi | 28.0 |
| GPa | 190 | |
| Melting Range | °F | 2372 – 2534 |
| °C | 1300 – 1390 | |
| Thermal Conductivity | Btu•in/ft2 •h•°F | 85 |
| W/m•°C | 12.3 | |
| Specific Gravity | 7.95 | |
| Magnetic Permeability | <1.02 | |
| Temperature Range | |||
| °F | °C | in/in/°F | cm/cm/°C |
| 68 – 212 | 20 – 100 | 8.5 x 10-6 | 15.3 x 10-6 |
| 68- 750 | 20-400 | 9.2 x 10-6 | 16.5 x 10-6 |
| 68-1475 | 20-800 | 10.1 x 10-6 | 18.2 x 10-6 |
| Yield Strength (0.2% Offset) | Ultimate Tensile Strength | Elongation in 2 in. | Hardness | |||
| psi | MPa | psi | MPa | % | Rockwell B | |
| Minimum ASTM & ASME | 31,000 | 220 | 71,000 | 490 | 36 | 70 – 90 |
| Typical Value | 39,500 | 270 | 88,000 | 605 | 50 | 79 |
Typical Values at 68°F (20°C) (minimum values, unless specified)
| Maximum Metal Temperatures | Maximum Allowable Stress per ASME | ||
| °F | °C | ksi | MPa |
| 100 | 38 | 17.8 | 123 |
| 200 | 93 | 16.7 | 115 |
| 300 | 149 | 15.1 | 104 |
| 400 | 204 | 13.8 | 95 |
| 500 | 260 | 12.7 | 88 |
| 600 | 316 | 12.0 | 83 |
| 700 | 371 | 11.4 | 79 |
| Boiling Solution | Corrosion Rate in MPY (mm/a) | |
| Steel Grade 316 | Steel Grade 904L | |
| 20% Acetic Acid | 0.1 (<0.01) | 0.6 (0.02) |
| 45% Formic Acid | 10.9 (0.28) | 7.7 (0.20) |
| 1% Hydrochloric Acid | 226 (5.74) | 21.6 (0.55) |
| 10% Oxalic Acid | 40.1 (1.02) | 27.1 (0.69) |
| 20% Phosphoric Acid | 0.20 (<.01) | 0.5 (0.01) |
| 10% Sodium Bisulfate | 41.5 (1.06) | 8.9 (0.23) |
| 50% Sodium Hydroxide | >100 (>2.5) | 9.6 (0.24) |
| 10% Sulfamic Acid | 63.6 (1.62) | 9.1 (0.23) |
| 10% Sulfuric Acid | 636 (16.2) | 101 (2.57) |
| Alloy | Temperature of Onset of Crevice Corrosion Attack*, °F (°C) |
| 316 | 27 (-3) |
| 317 | 35 (2) |
| 904L | 65 (18) |
| AL-6XN | 113 (45) |
| 625 | 113 (45) |
| AL 29-4C | 125 (52) |
*ASTM Procedure G-48, 10% Ferric Chloride Solution.
| Samples and Test Times to 1000 Hours | |||
| Boiling Solution | Alloy 316 | Alloy 904L | Alloy 20 |
| 42% Magnesium Chloride | Fail | Fail | Fail |
| 33% Lithium Chloride | Fail | Fail | Pass |
| 26% Sodium Chloride | Fail | Pass | Pass |
Fail = Chloride stress corrosion cracks observed. Pass = No cracking observed in testing.
| Intergranular Corrosion Resistance Test Procedure | Corrosion, Rates Mils per Year, (mm/a) | |
| Alloy 316 | Alloy 904L | |
| Copper-Copper Sulfate 16% Sulfuric Acid (ASTM A262 Practice E) Evaluated by Bend Test |
No Fissures | No Fissures |
| Ferric Sulfate Sulfuric Acid (ASTM A262 Practice B) |
35.5 (0.90) |
14.2 (0.36) |
| 65% Nitric Acid (ASTM A262 Practice C) |
34.3 (0.87) |
15.4 (0.39) |
| Steel Grade | Corrosion Rate, mm/year |
| 316L | >6 |
| 904L | 0.47 |
| 254 SMO® | 0.27 |
| 654 SMO® | 0.06 |
*Composition: 20% HNO3 + 4% HF.
| Steel Grade | Corrosion Rate, mm/year |
| 316L | >5 |
| 904L | 1.2 |
| 254 SMO® | 0.05 |
Composition: 54% P2O5, 0.06% HCl, 1.1% HF, 4.0% H2SO4, 0.27% Fe2O3, 0.17% Al2O3, 0.10% SiO2, 0.20% CaO and 0.70% MgO.
| Steel Grade | Corrosion Rate, mm/year |
| 316L | 0.88 |
| 317LMN | 0.29 |
| 904L | 0.06 |
| 254 SMO® | 0.01 |
904L Stainless delivers corrosion resistance exceeding standard austenitic grades, making it ideal for aggressive chemical environments. It is the most common of the “4% Molybdenum” alloys. It was originally developed to be an upgrade to 316L and Alloy 20 while remaining cheaper than Alloy C276. “6% Molybdenum” alloys such as AL6XN® have surpassed 904L Stainless in popularity.
904L Stainless is a non-magnetic, low-carbon, high-alloy austenitic stainless steel commonly used in environments where dependable corrosion resistance is required. Its high levels of nickel, chromium and molybdenum, along with the addition of copper, make it especially effective in protecting against aggressive media.
Its significant copper content improves its resistance to strong reducing acids, notably sulfuric, phosphoric, acetic and other organic acids, while high levels of nickel and molybdenum deliver superior resistance to chloride-induced stress corrosion cracking and pitting. UNS N08904 remains tough even at cryogenic temperatures and can be welded and fabricated without compromising corrosion resistance.
This alloy is composed of the following elements
The above composition conforms to ASTM material specifications for UNS N08904. For applications that require alternate chemistry or proprietary variants, please indicate that at the time of inquiry.
This alloy is also known as:
904L alloy is used for numerous applications:
Nickel Systems stocks a variety of fastener types made from SS904L, including:
Nickel Systems is your trusted supplier of premium 904L alloy fasteners that offer reliability and the expected corrosion resistance in suitable environments. Our extensive inventory allows us to ship hard-to-find items quickly, and we can provide expert assistance to help you pick the ideal products for your projects. Request a quote online today and benefit from our tailored, high-performance fastening solutions.
