304 Stainless steel pipe specification

ASTM A312 TP304/304L Stainless Steel Seamless Pipe, 304/304L SS Seamless and Welded Pipe Manufacturer

304 Stainless Steel Pipe is a metal pipe made of austenitic stainless steel, which contains 18% chromium and 8% nickel in its composition. Hunan Standard Steel Co., Ltd is a leading supplier and manufacturer of 304 stainless steel pipes of different types and sizes. The pipe specifications range from A312 and A358 in ASTM specifications. The size range meets ASTM, ASME and API standards. There are SS 304 seamless, welded and electric fusion welded pipes.

What is stainless steel pipe?

Stainless steel pipe is a long round steel material that is hollow and extends longitudinally. Stainless steel pipe is widely used in petroleum, chemical, medical, food, light industry, equipment and instruments, structural parts, etc. In addition, when the torsional strength and anti-torsion strength are equal, stainless steel is lighter, so it is often used in mechanical equipment parts and engineering structural parts, and is also commonly used as furniture and kitchen utensils, etc. Stainless steel pipes can be divided into seamless stainless steel pipes and welded stainless steel pipes according to the production process.

Stainless steel pipes have excellent corrosion resistance due to the addition of Ni and Cr chemical elements to adapt to different environments. Commonly used materials are 304/L and 316/L, and the standards are ASTM A312, A213, A270, etc. It is safe, reliable, hygienic, environmentally friendly, economical and applicable, and can resist corrosion from weak corrosive media such as air, steam, and water, and chemically corrosive media such as acids, alkalis, and salts.

What is 304 stainless steel pipe?

304 stainless steel pipe is a common stainless steel pipe with excellent corrosion resistance and beautiful surface. It is widely used in construction, decoration, machinery and other fields. ASTM A312 TP304 pipe is used for high pressure and high temperature applications because of its working temperature up to 870 degrees Celsius and high strength. SS UNS S30400 ERW pipe has a minimum yield strength of 205MPa and a minimum tensile strength of 515MPa. Applications include commercial, industrial, household and general corrosion services. ASME SA312 Grade 304 welded pipes are one of the most cost-effective stainless steel pipes on the market. These are also the most widely used stainless steel pipes in the world.

304 stainless steel material:
304 stainless steel is a brand of stainless steel produced in accordance with American ASTM standards (ASTM A312). It is a general-purpose stainless steel material with stronger anti-rust performance than 200 series stainless steel materials. It is also relatively good in terms of high temperature resistance and can reach temperatures as high as 1000℃-1200℃.

304 stainless steel has excellent stainless corrosion resistance and good intergranular corrosion resistance. For oxidizing acids, it was found in experiments that 304 stainless steel has strong corrosion resistance in nitric acid below the boiling temperature with a concentration of ≤65%. It also has good corrosion resistance to alkali solutions and most organic and inorganic acids.

304 seamless stainless steel pipe production process:
304 seamless stainless steel pipes are made from steel ingots or solid tube blanks that are perforated into capillary tubes, and then hot rolled, cold rolled or cold drawn. The production process mainly includes smelting, rolling, piercing, straightening, cutting and other links. Each link has its specific requirements and operating specifications. Only by strictly following the requirements can high-quality 304 stainless steel seamless pipes be produced.

Chemical composition of 304 stainless steel:
The chemical composition of 304 stainless steel mainly includes carbon (‌C)‌, ‌silicon (‌Si)‌, ‌manganese (‌Mn)‌, ‌chromium (‌Cr)‌, ‌nickel (‌Ni)‌, ‌sulfur (‌S)‌, ‌phosphorus (‌P)‌ and nitrogen (‌N)‌, the contents of chromium and nickel have a decisive influence on the performance of 304 stainless steel. ‌304 contains 18% chromium and 8% nickel. 304 is equivalent to China's 0Cr19Ni9 (0Cr18Ni9) stainless steel.

C：≤0.08 
Si ：≤1.0  
Mn：≤2.0 
Cr：18.0～20.0 
Ni ：8.0～10.5
S ：≤0.03 
P ：≤0.045 
N≤0.1。

304 stainless steel vs 304L stainless steel:

Both 304 stainless steel and 304L stainless steel are austenitic stainless steel, and the corrosion resistance of austenitic stainless steel comes from the chromium oxide protective layer formed on the surface of the stainless steel. The most basic difference between them is the chemical composition. "L" stands for low carbon. The carbon content of 304L stainless steel is less than 0.03; the carbon content of 304 is less than 0.08. The biggest feature of 304L stainless steel is its increased sensitivity to intergranular corrosion. The carbon content of the welded area is reduced without causing actual thermal sensitization problems. In terms of price, the price of 304L stainless steel is higher than that of 304 stainless steel. If 304L is used instead of 304, the cost will increase.

The types and specifications of 304 stainless steel pipes are usually classified according to their parameters such as outer diameter, wall thickness, length, etc. The types and specifications of 304 stainless steel pipes are introduced below.

The nominal inner diameter size of stainless steel 304 seamless pipe ranges from 1/8 inch to 16 inches, ERW pipe ranges from 1/8 inch to 24 inches, and EFW pipe ranges from 6 inches to 100 inches. All pipe sizes range from 1/8 inch to 30 inches. Stainless steel 304 welded pipes are welded from a narrow plate or strip. Seamless, welded or LSAW pipes come in a variety of shapes, including round, square, rectangular and hydraulic types.

ASTM A312 TP304/304L SS Seamless Pipe Material Specification:

Specifications	ASTM A 312 ASME SA 312 / ASTM A 358 ASME SA 358
Dimensions	ASTM, ASME and API
SS 304/304L Pipes	1/8″ NB – 16″ NB
ERW 304/304L Pipes	1/8″ NB – 24″ NB
EFW 304/304L Pipes	6″ NB – 100″ NB
Size	1/8″NB TO 30″NB IN
Specialized in	Large Diameter Size
Schedule	SCH 20, SCH 30, SCH 40, STD, XS, SCH 60, SCH 80, SCH 120, SCH 140, SCH 160, XXS
Type	Seamless / ERW / Welded / Fabricated / LSAW Pipes
Form	Round, Square, Rectangular, Hydraulic Etc
Length	Single Random, Double Random & Cut Length.
End	Plain End, Beveled End, Treaded

The following are common specifications of 304 stainless steel pipes:

1. Outer diameter: The outer diameter of 304 stainless steel pipes usually ranges from 1/8 inch (3.17mm) to 24 inches (609.6mm). Common outer diameter specifications include 1/4 inch, 1/2 inch, 3/4 inch, 1 inch, 1.5 inch, 2 inches, etc. Different outer diameter specifications can be selected according to different usage scenarios and needs.
2. Wall thickness: The wall thickness of 304 stainless steel pipes usually ranges from 0.035 inch (0.89mm) to 0.5 inch (12.7mm). Common wall thickness specifications include 0.049 inch, 0.065 inch, 0.083 inch, 0.109 inch, 0.120 inch, etc. Different wall thickness specifications can be selected according to different usage scenarios and needs.
3. Length: The length of 304 stainless steel pipes usually has 6 meters, 3 meters, 5.8 meters and other specifications to choose from. Different length specifications can be selected according to specific engineering needs.

In addition, there are some special 304 stainless steel pipe specifications, such as oval stainless steel pipe, square stainless steel pipe, rectangular stainless steel pipe, etc. These special specifications of stainless steel pipes are usually used in specific engineering and application fields.

Schedule Chart of ASTM A312 TP304/304L SS Welded Pipe:

Application fields of 304 stainless steel pipes

304 stainless steel pipes are widely used in the following fields:
1. Chemical industry: 304 stainless steel pipes are widely used in the chemical industry, such as manufacturing various chemical equipment, pipelines, valves, etc. Its excellent corrosion resistance can withstand the erosion of various corrosive media such as acids and alkalis.
2. Construction field: In the construction field, 304 stainless steel pipes are mainly used for decoration, railings, handrails, etc. Its beautiful appearance and excellent mechanical properties make it an ideal material for architectural decoration.
3. Mechanical equipment: 304 stainless steel pipes also occupy an important position in the field of mechanical equipment manufacturing. Such as manufacturing bearings, transmission parts, hydraulic systems, etc., its excellent mechanical properties and corrosion resistance can meet the needs of various complex working conditions.
4. Food processing: In the field of food processing, 304 stainless steel pipes are favored because of their non-toxic, odorless and easy to clean characteristics. It is widely used in the manufacture of various food processing equipment, pipelines, etc.
5. Other fields: In addition, 304 stainless steel pipes have also been widely used in environmental protection, medical equipment, shipbuilding and other fields.

Advantages and precautions of 304 stainless steel pipes:

304 stainless steel pipes have the advantages of corrosion resistance, beauty, hygiene and environmental protection, high strength, safety and reliability, etc., and can withstand corrosion from weak corrosive media such as air, steam, and water, and chemically corrosive media such as acids, alkalis, and salts. However, the following points should also be noted during use:

1. During installation, care should be taken to protect the surface of the pipe to avoid scratches or bumps.
2. When welding, the correct welding process should be followed to ensure the quality of welding.
3. Avoid heavy pressure and impact during transportation and storage to avoid deformation or damage.
4. Regular inspection and maintenance are required during use to ensure the normal use and safety and reliability of the pipe.

In short, as a common metal material, 304 stainless steel pipes have a wide range of applications and excellent performance characteristics. During use, attention should be paid to maintenance and care to ensure its safe and reliable performance.

Read more: 304 vs. 316 Stainless Steel: Which is Better? or Stainless Steel Seamless Pipe Manufacturing Process