Material Guide
304 vs 316 Stainless Steel: Which Liner for Your Flask
When sourcing drinkware, the liner material drives safety, corrosion resistance and cost. This guide compares food-grade 304 (18/8) and 316 (18/10) stainless steel on composition, performance and use cases so you can choose with confidence.
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What is 304 stainless steel (18/8)
304 is the most widely used food-grade austenitic stainless steel, with a typical composition of about 18% chromium and 8% nickel, which is why it is often called "18/8 stainless steel".
It offers good corrosion resistance and formability, and stays safe with everyday neutral drinks such as water, tea and coffee, making it the mainstream choice for drinkware liners worldwide.
- Chromium (Cr) ≈18%: forms a dense oxide film that resists rust
- Nickel (Ni) ≈8%: improves toughness and corrosion resistance
- No molybdenum (Mo): lower cost, widest versatility
What is 316 stainless steel (18/10)
316 belongs to the "medical / marine grade" of stainless steels, with a typical composition of about 16–18% chromium, 10% nickel, plus 2–3% molybdenum (Mo), i.e. "18/10 stainless steel".
The added molybdenum significantly improves pitting and chloride corrosion resistance, performing more reliably when holding acidic drinks, salt water or in humid coastal environments.
- Chromium (Cr) ≈16–18%
- Nickel (Ni) ≈10%
- Molybdenum (Mo) ≈2–3%: the key to chloride and acid corrosion resistance
- Higher cost than 304, positioned as premium
The core difference
For flask buyers, the biggest difference between 304 and 316 is the presence of molybdenum and the resulting chloride-corrosion resistance.
For everyday water and tea, 304 is more than enough. If the product is premium, often holds juice or sports drinks, or targets humid coastal markets, 316 delivers a longer service life and a safer margin.
How to choose when sourcing
Decide based on use case, market and budget:
- Choose 304: mass-market, neutral drinks, cost-sensitive, high-MOQ wholesale
- Choose 316: premium gift flasks, sports/acidic drinks, medical or baby scenarios, export to coastal/humid markets
- Both should be food-grade; ask suppliers for FDA, LFGB or equivalent test reports
Badun Trading material options
Badun Trading vacuum flasks support both food-grade 304 and 316 stainless steel liners, with Tritan / BPA-free plastic parts, and the whole flask can pass CE·FDA·LFGB food-grade certification.
We provide 3D samples (about 7–10 days) and mold samples (about 15–20 days) based on order quantity and process complexity; bulk production is typically 25–30 days. State your material and certification needs in the inquiry.
304 vs 316 stainless steel key parameters
| Item | 304 Stainless (18/8) | 316 Stainless (18/10) |
|---|---|---|
| Chromium (Cr) | ≈18% | ≈16–18% |
| Nickel (Ni) | ≈8% | ≈10% |
| Molybdenum (Mo) | None | 2–3% |
| Corrosion resistance | Enough for daily food use | Better; resists chloride and acid |
| Typical use | Flask liners, cutlery | Premium flasks, medical, sea, acidic drinks |
| Relative price | Lower | Higher (about 20–40% more) |
| Food-grade | Yes | Yes |
Frequently Asked Questions
Both are food-grade and safe for daily use. 316, with molybdenum, resists corrosion better with acidic drinks or in humid conditions, but it is "more durable" rather than "safer".
For most neutral drinks like water, tea and coffee, food-grade 304 is fully sufficient and is the industry mainstream. Upgrade to 316 only for premium, sports-acidic or coastal-market products.
If the product is a premium gift, sports bottle or exported to coastal markets, 316’s corrosion life and selling point justify the premium; for mass wholesale, 304 is more cost-effective.
Ask the supplier for a material report (e.g. SGS) and food-grade tests (FDA/LFGB), and do spot checks on bulk with reagent or spectrometer testing.
Need a material plan and quote?
Tell us your use case, market and quantity. Badun Trading matches a 304 or 316 liner solution and provides samples for confirmation.
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