What is grade 304 Stainless steel?

 

Stainless steel grades 304 and 304L are also known as 1.4301 and 1.4307; A2 stainless steel and 18/8 stainless steel. The latter is because it typically contains 18% chromium and 8% nickel. It is the most versatile and widely used grade of stainless steel.

 

Characteristics of grade 304:

• It has good forming and welding properties

• It is corrosion / oxidation resistant due to its chromium content

• Deep drawing quality (drawing longer than its diameter

• Excellent toughness at very low temperatures

• Low temperature properties respond well to hardening by cold working

• Ease of cleaning and beauty of appearance

 

• Forming and welding

• Grade 304 is ideal for forming. It is therefore made into a variety of components for applications in the architectural, industrial and transportation fields. It also has outstanding welding characteristics. Post-weld annealing is not necessary when welding thin sections.

 

• Corrosion resistance

• 304 stainless steel is highly resistant to rust. It can withstand corrosion from most oxidizing acids which makes it ideal for kitchen and food applications. However, 304 is susceptible to corrosion from chloride solutions (particularly saline environments with high amounts of sodium chloride). Chloride ions can create pitting (localised areas of corrosion) which can spread and compromise internal structures. Solutions containing as little as 25 ppm of sodium chloride can have this corrosive effect

• Deep drawing

• Stainless steel 304 has a balanced austenitic structure which enables it to be severely deep drawn without the need for intermediate annealing. It has made this grade dominant in the manufacture of drawn parts such as sinks, saucepans and tubing. For these type of applications it is common to request special "304DDQ" (Deep Drawing Quality) variants

• Type 304L and 304H

• Type 304L is a low carbon form of 304 and is used in heavy gauge components for improved weldability. Some products such as pipe and plate can be available as “dual certified” material that meets the criteria for both 304 and 304L.

• 304H is a high carbon content variant which is used for high temperatures

• Food industry

• Because of its ability to withstand the corrosiveness of acids found in fruits, meats, milk, and vegetables, stainless steel type 304 is used to make kitchen equipment, utensils and appliances. It is also especially suited for all types of dairy equipment including milking machines, homogenizers, sterilizers, storage tanks and piping. It is similarly used in the brewing industry for pipelines, yeast pans, fermentation vats and storage. Again, the fruit juice industry also uses 304 for all their crushing, preparation, storage and delivery equipment. In other food processing applications such as in mills, bakeries, and slaughter and packing houses, all the metal equipment exposed to acids, animal and vegetable oils and fats is manufactured from type 304.

• Industrial uses

• Type 304 stainless steel is used for the dye tanks, pipelines, buckets and dippers that come in contact with acetic, lormic and other organic acids used in the dyeing industry.

 

• In the marine environment, due to its high strength and wear resistance, 304 is used for nuts, bolts, screws and other fasteners. It’s also used for springs, cogs and other components where superior wear and corrosion resistance is required.

• Applications

• 304 stainless steel is typically used in:

• Sinks and splashbacks

• Saucepans

• Cutlery and flatware

• Architectural paneling

• Sanitary ware

• Tubing

• Brewery, dairy, food and pharmaceutical production equipment

• Springs, nuts, bolts and screws

• Table tops

• Coffee urns

• Stoves

• Refrigerators

• Steam tables