CS Seamless Pipes: ASTM A106, A53 & API 5L
Dinesh Tube India supplies carbon steel seamless pipes from Mumbai to EPC contractors, refineries, power plants, process plants and fabricators in India and abroad. We supply ASTM A106 Gr B, ASTM A53 Gr B and API 5L Gr B / X-grade CS seamless pipes from 1/2" to 24" NB, in SCH 10 to XXS, with an EN 10204 3.1 mill test certificate.
This page covers the main carbon steel seamless pipe grades, sizes and schedules. Each grade also has its own page with full technical data. Send us your grade, size, schedule, length and quantity for a quote.
What Is a Carbon Steel Seamless Pipe?
A carbon steel seamless pipe (often written CS seamless pipe or CS SMLS pipe) is made by piercing a solid steel billet and rolling or drawing it into a hollow, so there is no welded seam. Because the wall is uniform all the way round, seamless pipe is the standard choice for steam, high-pressure and high-temperature lines, where a weld seam could be the weak point.
Carbon steel pipes are ordered by nominal pipe size (NPS or NB) and schedule to ASME B36.10, unlike carbon steel tubes, which are ordered by actual OD and wall thickness for boilers and heat exchangers. The most common seamless grade is ASTM A106 Gr B, often supplied triple certified to A106 Gr B / A53 Gr B / API 5L Gr B.
Carbon Steel Seamless Pipe Grades Compared
ASTM A106 Chemical Composition
Values in weight %. The combined Cr, Cu, Mo, Ni and V must not exceed 1%.
ASTM A106 Mechanical Properties
Need CS seamless pipes for a project? Send your grade, size, schedule, length and quantity to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.
Carbon Steel Pipe Size & Schedule Chart (ASME B36.10)
Sizes up to 24" NB and other schedules (SCH 10 to XXS) on request.
Types of CS Seamless Pipes
ASTM A106 Gr B Pipes
ASTM A53 Gr B Pipes
API 5L Line Pipes
Looking for Low-Temperature Carbon Steel Pipes?
Standard carbon steel pipes like A106 and A53 are not impact tested and can become brittle in cold service. For temperatures down to −45 °C, use LTCS pipe to ASTM A333 Gr 6. See our dedicated low temperature carbon steel seamless pipes page for LTCS grades, impact test requirements and sizes, or the ASTM A333 Gr 6 pipes page.
Carbon Steel Seamless Pipe Applications
For steam and boiler piping in India, see our IBR pipes page. Matching A234 WPB fittings and A105 flanges are also available. For service above about 425 °C, see alloy steel pipes.
Carbon Steel Seamless Pipes: FAQs
What is a carbon steel seamless pipe?
A carbon steel seamless pipe (CS seamless pipe) is a pipe made from a solid steel billet that is pierced and rolled or drawn into a hollow, so it has no welded seam. Without a weld, it handles pressure and temperature evenly around the whole wall, which is why seamless pipe is preferred for steam, high-pressure and high-temperature lines. Common grades are ASTM A106 Gr B, ASTM A53 Gr B and API 5L Gr B.
What is the difference between ASTM A106 and ASTM A53 pipe?
ASTM A106 covers seamless carbon steel pipe for high-temperature service, and is the usual choice for refinery, power plant and steam piping. ASTM A53 covers seamless and welded pipe for general, lower-temperature service such as water, air and structural lines. For the same grade (Gr B), the minimum strength is the same, but A106 has tighter chemistry and is always seamless.
What is the difference between A106 Gr B and API 5L Gr B?
A106 Gr B is a process piping grade made for high-temperature service under ASME B31.3 and B31.1. API 5L Gr B is a line pipe grade for transporting oil, gas and water under pipeline codes such as ASME B31.4 and B31.8. Many mills certify pipe to A106 Gr B, A53 Gr B and API 5L Gr B together (triple certified), so one pipe can meet all three.
What temperature can carbon steel seamless pipe be used at?
ASTM A106 pipe is written for high-temperature service and is commonly used up to about 425 °C. Above that, long exposure can cause graphitisation, so alloy steel pipes such as ASTM A335 P11 or P22 are used. For service below about −29 °C, low-temperature carbon steel pipe (ASTM A333 Gr 6) is used instead.
What is a pipe schedule?
A pipe schedule (SCH) is a number that sets the wall thickness for each nominal pipe size under ASME B36.10. Higher schedules mean thicker walls: for a 4 in. pipe, SCH 40 is 6.02 mm, SCH 80 is 8.56 mm and SCH 160 is 13.49 mm. The outside diameter stays the same for a given size, so the bore gets smaller as the schedule increases.
Do you supply IBR carbon steel seamless pipes?
Yes. For steam lines and boilers in India, we supply ASTM A106 Gr B and other seamless pipes with IBR Form III-A certification from a Well Known Pipe Maker. State the IBR requirement in your enquiry so inspection can be arranged before dispatch.
Export Destinations for CS Seamless Pipes
We export carbon steel seamless pipes to the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq, Jordan), Africa (Nigeria, Egypt, South Africa, Kenya, Ghana, Algeria, Morocco, Tunisia), Asia (Japan, South Korea, Singapore, Malaysia, Indonesia, Thailand, Vietnam, Philippines, Bangladesh, Sri Lanka), Europe (Italy, Spain, Portugal, France, Netherlands, Belgium, Poland, Romania, Turkey, United Kingdom), and the Americas (United States, Canada, Mexico, Brazil, Chile, Peru, Colombia, Argentina).