Introduction
Stainless steel is a key material in highly regulated industries such as pharmaceuticals, biotechnology, food and hospitality. Its excellent corrosion resistance properties , ease of cleaning and durability make it the preferred choice for cleanrooms and containment equipment.
However, the choice between types 304, 316 and 316L can decisively affect the service life and performance of installations.
This article describes their main characteristics and discusses the criteria for choosing the most suitable alloy according to the environment of use.
Table of Contents
Characteristics of 304, 316 and 316L stainless steels
Chemical composition and corrosion resistance
Stainless steel is an iron alloy with at least 10.5% chromium, responsible for its ability to resist corrosion. The differences between grades 304, 316 and 316L lie mainly in their composition:
- 304 stainless steel: Contains about 18% chromium and 8% nickel, without molybdenum. It is considered versatile for general applications and dry environments, although it shows lower corrosion resistance in the presence of chlorides.
- 316 stainless steel: Includes 16-18% chromium, 10-14% nickel and 2-3% molybdenum. Provides better protection against pitting and crevice corrosion, especially in chloride environments.
- 316L stainless steel: It is similar to 316, but with a lower carbon content (<0.03%). This reduces the formation of carbides during welding and prevents intergranular corrosion.
316 and 316L steels are particularly resistant to aggressive disinfectants such as vaporized hydrogen peroxide (VH₂O₂), sodium hypochlorite and peracetic acid, making them suitable for environments with intensive cleaning or high sterility requirements.
Mechanical properties and ease of manufacture
Types 304, 316 and 316L belong to the austenitic family of steels and are therefore non-magnetic and non-hardenable by heat treatment. Their mechanical properties are similar, although 316L offers advantages in applications where frequent welding is performed, by minimizing the formation of carbides and, therefore, the risk of intergranular corrosion.
Clean room and industrial applications
The selection of the appropriate stainless steel depends on several factors, such as exposure to corrosive substances, frequency of cleaning and the need for chemical resistance. The most common uses for each grade are listed below.
304 stainless steel
Suitable when the risk of corrosion is low and cleaning does not require frequent use of aggressive chemicals:
- Containment and protection equipment (SAS, laminar flows, weighing booths) in low chemical risk environments.
- Modular panels and partitions for cleanroom construction where extreme chemical resistance is not a requirement.
- Doors and furniture in dry areas with little exposure to corrosive agents.
- Work surfaces and laboratory benches with limited contact with aggressive substances.
316 stainless steel
Recommended for applications requiring increased corrosion resistance and frequent maintenance with aggressive disinfectants:
- Containment and protection equipment (SAS, laminar flows, weighing booths) in high classification cleanrooms where strong biocides are applied.
- Ventilation and HVAC systems with components exposed to humidity or precision air conditioning.
- Surfaces in contact with saline solutions or chlorides, where corrosion resistance is essential.
316L stainless steel
Ideal for environments with complex welds or maximum corrosion resistance requirements:
- Pharmaceutical and biotechnological processing equipment (isolators, RABS, sterilization chambers) where high purity is required.
- Ducting and piping for critical fluids, such as water for injection (WFI) systems and high purity gases.
- Applications with highly corrosive agents, which require frequent cleaning and disinfection with intensive chemical products.
In the pharmaceutical and biotech industries, both 316 and 316L meet regulatory standards and are indispensable for applications where corrosion resistance and cleanability are priorities.
Conclusion
The choice between 304, 316 and 316L stainless steels depends on the conditions of use and the specific requirements of each installation. While 304 is an economical and versatile choice for general applications, 316 and 316L excel in environments with frequent exposure to chemicals and demands for sterility.
At Iguña, Kirhtech and Modular Clean Panel we can advise you to select the optimum material to meet your needs and ensure maximum efficiency and durability of your equipment and installations.
