What Material Is Used for the Inner Layer of Your Vacuum Bottles? Yes, It’s Stainless Steel 304

If you’re sourcing vacuum bottles or insulated mugs for the European or North American market, one of the first questions you’ll ask is: “What material is used for the inner layer?” The answer from Beisflask is clear: our double-wall vacuum bottles and mugs use Stainless Steel 304 (SS304) for the inner layer, ensuring food-safe contact with your beverages.

Take, for example, our Customized Logo Color Double-layer 304 Stainless Steel Mug. This product is explicitly described as a “304 double wall stainless steel mug travel cup” with the material specification SS304+SS201 — meaning the inner layer is food-grade 304 stainless steel, while the outer layer uses SS201 for structural strength and cost efficiency. This design is common in premium insulated drinkware: the inner surface that comes into direct contact with coffee, milk, tea, or water is 304 stainless steel, which is widely recognized for its corrosion resistance and food safety.

Why Stainless Steel 304 Matters for Food Contact

Stainless steel 304 is an austenitic chromium-nickel alloy that is one of the most commonly used food-grade materials worldwide. It does not impart taste, is resistant to acidic beverages, and is safe for repeated use. When exporting to the EU and the US, regulators require that food-contact materials meet strict migration limits. Beisflask ensures that all products — including the 304-lined vacuum mugs — are BPA free and can pass the tests of FDA (US Food and Drug Administration), CA65 (California Proposition 65), and LFGB (German Food and Feed Code). This means your bottles and mugs meet the chemical safety requirements for direct food contact in major Western markets.

Compliance and Quality Assurance at Beisflask

Zhejiang Beisheng Industry & Trading Co., Ltd., the company behind the Beisflask brand, is a dedicated drinkware manufacturer and exporter established in 2018. We specialize in stainless steel drinkware including vacuum bottles, mugs, tumblers, and coffee cups. Beyond material safety, our factory has passed the audits of BSCI, Sedex 2P, and GSV, confirming our commitment to ethical manufacturing, social responsibility, and supply chain security. These certifications are essential for brands selling into EU and US retail channels.

Customization and Export-Ready Features

This 304 stainless steel double-wall mug is available in 12 oz capacity with customizable colors and logos (5D UV printing or laser engraving). The minimum order quantity is 1000 pieces, and samples are free. Packing is 1 piece per opp bag, with delivery time of 3–7 days. All products comply with European and American food safety standards, making this mug a reliable choice for coffee shops, promotional giveaways, or retail brands looking for safe, high-quality insulated drinkware.

So, to answer your question directly: Yes, the inner layer of our vacuum bottles and mugs is stainless steel 304 — the same food-grade material trusted by global brands. When you choose Beisflask, you’re choosing material safety, compliance, and quality craftsmanship for the demanding US and EU markets.