Table of Contents
- 304 vs 316 Stainless Overview
- 304 Stainless Steel: The Industry Standard
- 316 Stainless Steel: Enhanced Corrosion Resistance
- Side-by-Side Comparison
- Selection Guide by Application
- Frequently Asked Questions
- Get Your Quote
304 and 316 stainless steel are the two most widely used austenitic grades for CNC machining. While they look similar and share many properties, their differences matter significantly in certain applications.
304 Stainless Steel: The Industry Standard
304 (1.4301 or 18/8 stainless) is the most common stainless steel grade worldwide. It contains 18% chromium and 8% nickel, providing good corrosion resistance and excellent formability.
Key specs:
- Tensile strength: 515 MPa (75,000 psi)
- Yield strength: 205 MPa (30,000 psi)
- Machinability: 45% (compared to 1212 carbon steel)
- Corrosion resistance: Good (general purpose)
- Cost: $$
Best for: Food equipment, kitchen equipment, general industrial parts, fasteners
316 Stainless Steel: Maximum Corrosion Protection
316 (1.4401) adds molybdenum to the chromium-nickel matrix, dramatically improving resistance to chlorides, acids, and salt water.
Key specs:
- Tensile strength: 485 MPa (70,000 psi)
- Yield strength: 170 MPa (25,000 psi)
- Machinability: 40% (slightly more gummy than 304)
- Corrosion resistance: Excellent (especially against chlorides)
- Cost: $$$
Best for: Medical instruments, pharmaceutical equipment, marine components, chemical equipment
Side-by-Side Comparison
| Property | 304 | 316 |
|---|---|---|
| Chromium | 18-20% | 16-18% |
| Nickel | 8-10.5% | 10-14% |
| Molybdenum | None | 2-3% |
| Tensile Strength | 515 MPa | 485 MPa |
| Machinability | 45% | 40% |
| Chloride Resistance | Good | Excellent |
| Cost Factor | 1.0x | 1.3-1.5x |
Selection Guide by Application
Choose 304 when:
- Environment is non-marine, non-chemical
- Budget is a consideration
- Better machinability is needed
Choose 316 when:
- Parts contact salt water or de-icing salts
- Application involves acidic foods or chemicals
- Medical or pharmaceutical use
Frequently Asked Questions
Q: Can you machine 316L instead of 316?
A: Yes. 316L (low carbon) is preferred for welded assemblies as it resists intergranular corrosion.
Q: Is 316 always better than 304?
A: No. 316 is better in corrosive environments, but 304 has slightly higher strength and is more cost-effective for general applications.
Need CNC Machined Stainless Parts?
Contact us with your application details. We will help you select the right grade and provide a quote within 24 hours.