Stainless for food equipment: 304 or 316L, and how smooth the surface must be

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food equipment · 304 · 316L · hygienic design

304 is common for general food contact; 316L for acidic, salty or aggressive cleaning media. Hygienic design depends on Ra, weld quality and cleanability.

Food and beverage equipment selection balances corrosion resistance and hygiene:

1) Grade: 304 is common for general food contact (water, dairy, grain); 316L is preferred for acidic media, salt or chloride cleaning agents such as sodium hypochlorite.
2) Surface: contact surfaces often require Ra ≤0.8 μm depending on the standard; 2B/BA or polished finishes; welds must be smooth, free of heat tint and pickled/passivated.
3) Hygienic design: avoid dead legs, crevices and trapped liquid; provide drainage slope and drainability; food-grade seals.
4) Standards: reference EHEDG, 3-A sanitary standards and customer specifications.
5) Verification: cleaning validation (CIP) and passivation records.

Common mistakes:

• Assuming 316L cannot corrode — concentrated chloride cleaner residue still causes pitting.
• Focusing on grade while ignoring welds and roughness — microbial retention often occurs at welds and rough surfaces.
• Cleaning with carbon steel brushes/tools — introduces free iron contamination.

Purchasing advice: state grade, surface Ra, weld requirements, passivation and cleaning validation in the technical agreement.

本文由 SteelWe 编辑与行业专家整理，内容仅供行业交流参考，不构成交易或投资建议。引用请注明来源。

Stainless for food equipment: 304 or 316L, and how smooth the surface must be

304 is common for general food contact; 316L for acidic, salty or aggressive cleaning media. Hygienic design depends on Ra, weld quality and cleanability.

Food and beverage equipment selection balances corrosion resistance and hygiene:

1) Grade: 304 is common for general food contact (water, dairy, grain); 316L is preferred for acidic media, salt or chloride cleaning agents such as sodium hypochlorite.
2) Surface: contact surfaces often require Ra ≤0.8 μm depending on the standard; 2B/BA or polished finishes; welds must be smooth, free of heat tint and pickled/passivated.
3) Hygienic design: avoid dead legs, crevices and trapped liquid; provide drainage slope and drainability; food-grade seals.
4) Standards: reference EHEDG, 3-A sanitary standards and customer specifications.
5) Verification: cleaning validation (CIP) and passivation records.

Common mistakes:

• Assuming 316L cannot corrode — concentrated chloride cleaner residue still causes pitting.
• Focusing on grade while ignoring welds and roughness — microbial retention often occurs at welds and rough surfaces.
• Cleaning with carbon steel brushes/tools — introduces free iron contamination.

Purchasing advice: state grade, surface Ra, weld requirements, passivation and cleaning validation in the technical agreement.

本文由 SteelWe 编辑与行业专家整理，内容仅供行业交流参考，不构成交易或投资建议。引用请注明来源。