Materials
Stainless Steel
Comparison
OEM Guide
Choosing between 304 and 316 stainless steel is one of the most common questions in manufacturing.
This guide explains the differences in composition, corrosion resistance, cost, and applications — helping you make the right choice for your project.
Quick Answer
304 SS: 18% Cr, 8% Ni. Excellent for most applications. Lower cost.
316 SS: 16-18% Cr, 10-14% Ni, 2-3% Mo. Superior corrosion resistance. Higher cost (~20-30%).
Comparison Table
| Property |
304 Stainless Steel |
316 Stainless Steel |
| Chromium |
18-20% |
16-18% |
| Nickel |
8-10.5% |
10-14% |
| Molybdenum |
None |
2-3% |
| Corrosion Resistance |
Excellent (general) |
Superior (chlorides) |
| Pitting Resistance |
Good (PREN ~18) |
Excellent (PREN ~24) |
| Cost |
Lower (baseline) |
Higher (~20-30% more) |
| Weldability |
Excellent |
Excellent (use 316L filler) |
| Machinability |
Good |
Good (slightly harder) |
| Typical Applications |
Coffee, kitchen, food prep |
Marine, coastal, chemical |
Detailed Comparison
1. Chemical Composition
304 Stainless Steel (also called "18-8" SS) contains approximately 18% chromium and 8% nickel.
It is the most common stainless steel grade, accounting for ~50% of global stainless steel production.
316 Stainless Steel adds 2-3% molybdenum (Mo), which significantly enhances corrosion resistance.
The nickel content is also higher (10-14%) for improved ductility and toughness.
2. Corrosion Resistance
Both grades offer excellent corrosion resistance in most environments. However, 316 SS outperforms 304 in chloride-rich environments:
- Seawater: 316 SS resists pitting and crevice corrosion; 304 will corrode over time.
- Deicing salts: 316 SS is preferred for coastal roads and bridges.
- Chemical exposure: 316 SS resists acids (sulfuric, hydrochloric) better than 304.
- Food processing: Both are food-grade, but 316 is preferred for salty foods (brine, seafood).
3. Pitting Resistance Equivalent Number (PREN)
PREN is a quantitative measure of pitting corrosion resistance:
- 304 SS: PREN ≈ 18-20 (good)
- 316 SS: PREN ≈ 24-26 (excellent)
- 316L SS: PREN ≈ 24-26 (same as 316, lower carbon)
Rule of thumb: If PREN < 24, avoid chloride exposure. Choose 316 (PREN ~24) for coastal or marine applications.
4. Cost Difference
316 SS typically costs 20-30% more than 304 SS. The price premium comes from:
- Higher nickel content (Ni is expensive)
- Molybdenum addition (Mo is expensive)
- Lower global production volume (less economies of scale)
BONRAY's experience: For OEM projects, upgrading from 304 to 316 adds ~$0.50-$1.50 per kg to material cost, depending on market prices.
Pros and Cons
✅ 304 Stainless Steel — Pros
- Lower cost (baseline)
- Excellent for most food-grade applications
- Easy to weld and machine
- Widely available (short lead time)
- Sufficient for coffee/kitchen equipment
❌ Cons
- Poor resistance to chlorides (seawater, salt)
- May corrode in coastal environments
- Not suitable for chemical processing
✅ 316 Stainless Steel — Pros
- Superior corrosion resistance (chlorides)
- Ideal for marine/coastal applications
- Better chemical resistance
- Preferred for medical implants
- Higher resale value (durability)
❌ Cons
- 20-30% more expensive than 304
- Slightly harder to machine (work hardening)
- Overkill for indoor/non-corrosive applications
Application Guide — Which Should You Choose?
✅ Choose 304 SS for:
- Coffee brewing equipment: Pour-over drippers, espresso accessorries, brewing kettles. Coffee is mildly acidic (pH 4.5-5.5) and does not contain chlorides.
- Commercial kitchens: Prep tables, sinks, shelving, food prep tools.
- Indoor applications: Anywhere without exposure to seawater, deicing salts, or harsh chemicals.
- Cost-sensitive projects: When budget is tight and corrosion risk is low.
✅ Choose 316 SS for:
- Marine/coastal applications: Boat hardware, dock equipment, coastal outdoor kitchens. Salt air will corrode 304 over time.
- Chemical processing: Equipment exposed to acids, alkalis, or solvents.
- Seafood processing: Brine, salted fish, shellfish — high chloride content.
- Medical implants: Surgical instruments, implants (316L, low carbon).
- Pharmaceutical: Equipment requiring frequent sterilization (high-temperature steam).
BONRAY's Recommendation
For coffee brewing equipment and commercial kitchens: 304 SS is sufficient.
For coastal locations or seafood processing: Upgrade to 316 SS.
Still unsure? Contact our engineering team for a free material selection consultation.
Frequently Asked Questions
Q: Can I use 304 SS for outdoor applications?
A: Yes, but avoid coastal locations. For inland outdoor use (no seawater/salt exposure), 304 SS is fine. For coastal outdoor use, choose 316 SS.
Q: Is 316 SS worth the extra cost for coffee equipment?
A: No. Coffee is mildly acidic and does not contain chlorides. 304 SS is sufficient and will last for decades. Save the budget for better surface finish (mirror polish) or thicker gauge steel.
Q: Can 304 and 316 SS be welded together?
A: Yes, but use 316L filler rod. The weld seam may be less corrosion-resistant than the base materials. For critical applications, avoid mixing grades.
Q: Does BONRAY offer both 304 and 316 SS for OEM orders?
A:
Yes. BONRAY stocks both 304 and 316 stainless steel coils/sheets. We can manufacture your OEM order in either grade.
Get a quote for both options to compare cost.
Need Help Choosing the Right Stainless Steel Grade?
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