Table of Contents
What is 304 Stainless Steel PM Material?
304 stainless steel is an austenitic stainless steel (18% chromium, 8% nickel) widely used in powder metallurgy for corrosion-resistant applications. It offers excellent corrosion resistance, good formability, and is non-magnetic.
Material Designation
- AISI/ASTM: 304, 304L (low carbon version)
- UNS: S30400, S30403
- Alternative Names: 18-8 Stainless
Chemical Composition
| Element | Weight % |
|---|---|
| Chromium (Cr) | 18-20% |
| Nickel (Ni) | 8-10.5% |
| Carbon (C) | <0.08% (304) or <0.03% (304L) |
| Manganese (Mn) | <2% |
| Silicon (Si) | <1% |
| Iron (Fe) | Balance |
304L vs 304: Lower carbon content in 304L improves weldability and reduces carbide precipitation.
Mechanical Properties
Sintered Condition (Density 6.8-7.0 g/cm3)
| Property | Typical Value |
|---|---|
| Tensile Strength | 450-550 MPa (65-80 ksi) |
| Yield Strength | 250-350 MPa (36-51 ksi) |
| Elongation | 8-15% |
| Hardness | 70-85 HRB |
High Density (>7.2 g/cm3, via infiltration or HIP)
| Property | Typical Value |
|---|---|
| Tensile Strength | 550-650 MPa (80-95 ksi) |
| Yield Strength | 300-400 MPa (44-58 ksi) |
| Elongation | 15-25% |
Note: Properties strongly depend on density. Higher density = better properties.
Key Advantages
- Excellent Corrosion Resistance - Marine, food, medical environments
- Non-Magnetic - Suitable for electronic/magnetic-sensitive applications
- Good Ductility - Better than 316L, easier to form
- Food-Safe - FDA-approved for food contact
- Weldable - Especially 304L version
Typical Applications
Medical Devices
- Surgical instruments
- Implant components (non-load bearing)
- Sterilization equipment parts
Food & Beverage
- Pump components
- Valve bodies
- Filter housings
- Fasteners and fittings
Marine & Chemical
- Corrosion-resistant brackets
- Fasteners for marine use
- Chemical processing equipment
Electronics
- Non-magnetic housings
- Shielding components
- Precision springs
Corrosion Resistance
Excellent Against:
- Atmospheric corrosion
- Mild acids and alkalis
- Food acids (citric, acetic)
- Fresh water and steam
Limited Resistance:
- Chloride environments (pitting may occur)
- Strong acids (HCl, H鈧係O鈧?
- Salt spray (316L is better)
For Marine/Chloride Environments: Use 316L stainless steel instead.
Processing Parameters
- Compaction Pressure: 600-800 MPa
- Sintering Temperature: 1250-1300°C
- Sintering Atmosphere: High-purity hydrogen or vacuum
- Sintering Time: 30-60 minutes
- Typical Density: 6.8-7.2 g/cm3
Challenge: Stainless steel requires higher sintering temperature and purer atmosphere than carbon steel.
Secondary Operations
Common:
- Polishing (improve corrosion resistance and aesthetics)
- Passivation (nitric acid treatment)
- Machining (for precision features)
Optional:
- Electropolishing (smooth surface)
- Tumbling (deburr)
Not Recommended:
- Heat treatment (austenitic, cannot be hardened by heat treatment)
Design Considerations
Suitable For:
Corrosive environments Food/medical applications Non-magnetic requirements Moderate strength needs
Not Suitable For:
鉂?High strength applications (use 17-4PH or 420SS) 鉂?Marine/saltwater (use 316L instead) 鉂?Heat treatable hardness (use martensitic 410/420)
Material Comparison
| Material | Corrosion Resistance | Strength | Magnetic | Cost | Applications |
|---|---|---|---|---|---|
| 304 SS | Excellent | Medium | No | $$$ | Food, medical |
| 316L SS | Superior | Medium | No | $$$$ | Marine, implants |
| 17-4PH SS | Good | High | Yes | $$$$ | Aerospace, high-strength |
| 410 SS | Good | High | Yes | $$$ | Hardened tools |
| 420 SS | Good | Very High | Yes | $$$ | Cutting tools |
Cost Estimate
Material Cost: $15-25/kg (powder) Processing Cost: High (high-temperature sintering, special atmosphere) Typical Part Cost: 3-5x carbon steel PM parts
Cost Drivers:
- Expensive nickel and chromium content
- High sintering temperature (energy cost)
- Special atmosphere requirements
Quality Standards
- ASTM F899 - Stainless Steel PM for Surgical Implants
- MPIF Standard 35 - PM Stainless Steel Specifications
- ASTM A959 - Stainless Steel PM Structural Parts
Get 304 Stainless Steel PM Parts from SinterWorks
SinterWorks manufactures 304 SS PM components with:
- High-purity sintering atmosphere (dew point <-40°C)
- Density control: 6.8-7.2 g/cm3
- Passivation and electropolishing available for clean-service and corrosion-sensitive applications
Request a quote: Upload your drawing for free evaluation.
Frequently Asked Questions
Can 304 SS be heat treated?
No. It is austenitic and does not respond to heat treatment. Use 17-4PH or 420 for hardenable stainless.
Is 304 SS magnetic?
Generally non-magnetic, but may become slightly magnetic after cold working.
What is the difference between 304 and 304L?
304L has lower carbon (<0.03% vs <0.08%), which improves weldability and reduces sensitization to intergranular corrosion.
Can 304 SS be used in seawater?
Not recommended. Chlorides cause pitting. Use 316L for marine environments.
Related Resources
Use these internal links to keep moving through the most relevant guides, service pages, and technical references for this topic.
316L Material Guide
Compare 304 with 316L when chloride resistance, weldability, and corrosion margin matter in clean-service applications.
410 Stainless Steel PM
Review a hardenable stainless PM route when wear resistance or magnetism matters more than maximum corrosion resistance.
Surface Treatments
See how passivation, electropolishing, and finishing can influence the final surface condition of corrosion-sensitive PM parts.
Request a Quote
Send your corrosion environment, cleanliness requirement, and drawing for 304 stainless PM review and quotation support.