Alloy Steel Welded Tubes Manufacturer in India
Alloy Steel Welded Tubes Manufacturer in India
Sachiya Steel International is a leading Alloy Steel Welded Tubes Manufacturer in India, offering precisely engineered welded tubes for industries that require strength, durability, and dependable performance under demanding operating conditions. Our alloy steel welded tubes are available in various grades, dimensions, thicknesses, and finishes to suit applications such as power generation, petrochemical, oil & gas, chemical processing, refineries, and heavy engineering.
We focus on consistent manufacturing quality, accurate dimensions, and reliable material performance across every order. Our tubes can be supplied with relevant inspection reports, test certificates, and documentation according to customer requirements and applicable international standards. With extensive industry experience and export expertise,We serve distributors, stockists, fabricators, and project-based customers in India and international markets.
What Are Alloy Steel Welded Tubes?
Alloy Steel Welded Tubes are tubular products manufactured by forming alloy steel plates or strips into a cylindrical shape and joining the edges through a controlled welding process. The addition of elements such as chromium, molybdenum, nickel, and manganese improves their strength, toughness, corrosion resistance, and ability to withstand high temperatures and pressure.
These tubes are commonly used in demanding industrial environments where reliable performance and dimensional consistency are important. Alloy Steel Welded Tubes are widely used in power plants, boilers, heat exchangers, refineries, petrochemical plants, oil & gas systems, and other engineering applications. Depending on the application, they can be supplied in different grades, sizes, wall thicknesses, and specifications to meet required operating conditions and industry standards.
Pipes & Tubes
High-quality industrial pipes and tubes manufactured for demanding applications across chemical, petrochemical, power generation, marine, construction and engineering industries. Available in multiple materials, sizes, wall thicknesses and manufacturing specifications.
Types of Alloy Steel Welded Tubes
As an experienced Alloy Steel Welded Tubes Supplier, Stainless Steel Pipe Manufacturers offers welded tubes in different grades, conditions, and finishes to meet specific industrial requirements:
- Low-Temperature Tubes: ASTM A334 Grades 3, 7, and 9, developed for applications requiring reliable impact strength at low temperatures.
- Weathering Low-Alloy Tubes: ASTM A423 Grades 1 and 2, containing alloying elements that provide improved resistance to atmospheric corrosion.
- Molybdenum Steel Tubes: EN 10217-2 and 16Mo3 tubes designed for pressure applications and moderate-temperature service.
- Chrome-Moly Mechanical Tubes: ASTM A513 grades such as 4130 and 4140, commonly used for shafts, frames, machined components, and engineering applications.
- As-Welded Tubes: Supplied in their welded condition, with the weld bead trimmed for general industrial use.
- Normalised Tubes: Heat-treated and air-cooled to provide a more uniform structure and improve consistency around the weld area.
- Cold-Sized Tubes: Further processed after welding to achieve closer dimensional tolerances and improved surface accuracy.
- Black, Oiled & Varnished Tubes: Available with different surface finishes for protection during storage, transportation, and subsequent fabrication.
A334 Gr 3, A334 Gr 7, A334 Gr 9, A423, 16Mo3 and 4130 Alloy Steel Welded Tubes Manufacturers and Suppliers in India
We manufacture and supply Alloy Steel Welded Tubes in A334 Grade 3, A334 Grade 7, A334 Grade 9, A423, 16Mo3, 4130, and 4140 grades. Other grades can also be quoted upon request.
Popular sizes are maintained in ready stock, subject to availability, while other sizes can be manufactured to order.
- A334 Grade 3: Suitable for low-temperature service, including applications approaching −100°C.
- A334 Grade 7 & Grade 9: Suitable for moderate low-temperature applications where cost efficiency is important.
- A423: Recommended for outdoor and structural applications where corrosion resistance is a key requirement.
- 16Mo3: Suitable for pressure tubes and components operating at elevated temperatures.
- 4130 & 4140: Ideal for machine-building applications, particularly where components require heat treatment after machining.
When selecting reliable Alloy Steel Welded Tube Manufacturers and Suppliers in India, documentation and material traceability are essential. Our certificates clearly specify the material grade, applicable standard, and heat-treatment condition, providing buyers with the documentation required for quality assurance and inspection.
Types of Pipes & Tubes
Explore our range of industrial pipes and tubes, manufactured for different applications, materials, specifications and engineering requirements.
Pipes and Tubes
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Seamless Pipes
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ERW Pipes
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LSAW Pipes
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SSAW Pipes
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Seamless Tubes
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Welded Pipes
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Welded Tubes
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Box Pipes
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Box Tubes
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Brass Pipes
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Heat Exchanger Tubes
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Boiler Tubes
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Aluminium Pipes
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Carbon Steel Seamless Pipes
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Carbon Steel Pipe
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Stainless Steel Pipe
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Alloy Steel Pipe
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Duplex Steel Pipe
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Super Duplex Steel Pipe
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Nickel Alloy Pipe
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Copper Nickel Alloy Pipe
→Get Certified Alloy Steel Welded Tubes at Competitive Factory Prices
Alloy Steel Welded Tubes Specification
This table sets out the working specification of our Alloy Steel Welded Tubes.
| Item | Detail |
|---|---|
| Product | Alloy Steel Welded Tubes |
| Process | Longitudinal electric resistance welding (ERW), seam heat treated |
| Raw material | Alloy steel strip |
| Main grades | A334 Gr 3, 7, 9; A423 Gr 1, 2; 16Mo3; AISI 4130, 4140 |
| Tube standards | ASTM A334, A423, A513; EN 10217-2; EN 10296-1 |
| Size basis | Outside diameter × wall thickness (mm) |
| Size reference | OD 12.7 to 101.6 mm in the chart, other sizes on request |
| Length | Random, fixed or cut length |
| Finish | As-welded, cold sized, black, oiled or varnished |
| Ends | Plain ends, cut square and deburred |
| Heat treatment | Normalised, or normalised and tempered, as the grade requires |
| Tests | Chemical analysis, tensile, flattening, flaring, impact test where specified, hydrostatic or eddy current test |
| Certificate | EN 10204 3.1 with every order, 3.2 on request |
| Inspection | Third-party inspection on request |
Alloy Steel Welded Tubes Standards and Specifications
Alloy Steel Welded Tubes are bought against one product standard and checked against a general standard. The table links each standard to its use.
| Standard | Scope | Where it fits |
|---|---|---|
| ASTM A334 | Seamless and welded carbon and alloy tubes for low-temperature service | Cold process and refrigeration tubes |
| ASTM A423 | Seamless and electric-welded low-alloy tubes | Weathering and general low-alloy use |
| ASTM A513 | Electric-resistance-welded carbon and alloy mechanical tubing | Machined parts, cylinders, frames |
| ASTM A450 | General requirements for carbon and low-alloy tubes | Tolerances and test rules |
| EN 10217-2 | Electric welded non-alloy and alloy tubes with elevated-temperature properties | 16Mo3 pressure tubes |
| EN 10296-1 | Welded circular tubes for mechanical and general engineering | Structural and machine parts |
| EN 10204 | Types of inspection documents | 3.1 and 3.2 certificates |
Alloy Steel Welded Tubes Material and Grades
The table below ties each grade to its numbers and its best use.
| Grade | UNS | EN number (closest) | Best use |
|---|---|---|---|
| A334 Gr 3 | K31918 | 1.5637 (12Ni14) | Tubes at about −101°C |
| A334 Gr 7 | K21903 | — | Cold tubes with 2.5% nickel |
| A334 Gr 9 | K22035 | — | Cold tubes down to about −73°C |
| A423 Gr 1 / Gr 2 | — | — | Weathering low-alloy tubes |
| 16Mo3 | — | 1.5415 | Warm pressure tubes |
| AISI 4130 | G41300 | 1.7218 (25CrMo4) | Frames, cylinders, machined parts |
| AISI 4140 | G41400 | 1.7225 (42CrMo4) | Higher-strength sleeves, shafts |
What Is the Difference Between Alloy Steel Welded Tubes and Alloy Steel Seamless Tubes?
The short answer: welded tubes are rolled from strip and have one weld seam, while seamless tubes are pierced from a solid billet and have none. Welded tube costs less, has very even walls and ships faster. Seamless tube is the pick for the highest pressures and temperatures, and for the creep-strength chrome-moly grades.
| Factor | Welded tubes | Seamless tubes | When to pick welded |
|---|---|---|---|
| Raw material | Alloy strip | Alloy billet | You want lower material cost |
| Seam | One heat-treated weld | None | The code allows a welded tube |
| Wall evenness | Very even | Can vary more | You need a consistent wall |
| Pressure and heat | Moderate | Highest | Duty is cold or moderate |
| Chrome-moly boiler grades (T11, T22, T91) | Not covered | Covered by ASTM A213 | Not applicable |
| Price and lead time | Lower, faster | Higher, longer | Budget or time is tight |
| Typical jobs | Cold service, mechanical parts | Boilers, superheaters | Cold lines or machined parts |
Alloy Steel Welded Tubes Chemical Composition
Chemistry sets toughness and strength. The first table shows the low-temperature A334 grades, one element per row. Values are percentage by weight, maximum unless shown as a range. A dash means no limit.
| Element | A334 Gr 3 | A334 Gr 7 | A334 Gr 9 |
|---|---|---|---|
| Carbon (C) | 0.19 | 0.19 | 0.20 |
| Manganese (Mn) | 0.31–0.64 | 0.90 | 0.40–1.06 |
| Silicon (Si) | 0.18–0.37 | — | — |
| Nickel (Ni) | 3.18–3.82 | 2.03–2.57 | 1.60–2.24 |
| Copper (Cu) | — | — | 0.75–1.25 |
| Phosphorus (P) | 0.025 | 0.025 | 0.030 |
| Sulphur (S) | 0.025 | 0.025 | 0.030 |
The second table covers the molybdenum and chrome-moly tubes, with one grade per row.
| Grade | C | Mn | Si | Cr | Mo |
|---|---|---|---|---|---|
| 16Mo3 | 0.12–0.20 | 0.40–0.90 | 0.35 max | 0.30 max | 0.25–0.35 |
| AISI 4130 | 0.28–0.33 | 0.40–0.60 | 0.15–0.35 | 0.80–1.10 | 0.15–0.25 |
| AISI 4140 | 0.38–0.43 | 0.75–1.00 | 0.15–0.35 | 0.80–1.10 | 0.15–0.25 |
For 16Mo3, nickel and copper are each limited to 0.30% maximum, and phosphorus to 0.025% maximum.
Alloy Steel Welded Tubes Mechanical Properties
Mechanical properties tell you how much load the tube takes and how it behaves in the cold. The table gives minimum values.
| Grade | Yield min (MPa) | Tensile (MPa) | Elongation min (%) | Impact test at (°C) |
|---|---|---|---|---|
| A334 Gr 3 | 240 | 450 min | 30 | −101 |
| A334 Gr 7 | 240 | 415 min | 30 | −101 |
| A334 Gr 9 | 315 | 435 min | 28 | −73 |
| 16Mo3 (wall up to 16 mm) | 280 | 450–600 | 22 | — |
For AISI 4130 and 4140, strength depends on the heat treatment you order, so we quote against your required condition.
Alloy Steel Welded Tubes Size and Weight Chart
Weight depends on OD and wall thickness. We calculate it with the standard formula for carbon and low-alloy steel:
OD and wall are in mm. Example: a 50.8 mm OD tube with a 2.5 mm wall weighs (50.8 − 2.5) × 2.5 × 0.02466 = 2.98 kg/m. Multiply by length for the weight of the lot.
| OD (mm) | 1.6 mm wall | 2.0 mm wall | 2.5 mm wall | 3.2 mm wall |
|---|---|---|---|---|
| 12.7 | 0.44 | 0.53 | 0.63 | 0.75 |
| 19.05 | 0.69 | 0.84 | 1.02 | 1.25 |
| 25.4 | 0.94 | 1.15 | 1.41 | 1.75 |
| 31.75 | 1.19 | 1.47 | 1.80 | 2.25 |
| 38.1 | 1.44 | 1.78 | 2.19 | 2.75 |
| 50.8 | 1.94 | 2.41 | 2.98 | 3.76 |
| 63.5 | 2.44 | 3.03 | 3.76 | 4.76 |
| 76.2 | 2.94 | 3.66 | 4.54 | 5.76 |
| 88.9 | 3.44 | 4.29 | 5.33 | 6.76 |
| 101.6 | 3.95 | 4.91 | 6.11 | 7.76 |
All weights above are in kg/m.
Available Sizes, Dimensions and Tolerances
Alloy Steel Welded Tubes are ordered by OD, wall and length. The chart above covers OD 12.7 to 101.6 mm, and other sizes can be quoted on request. Tolerance depends on the standard you name. As a guide, EN 10217-2 allows the OD to vary by ±1% or ±0.5 mm, whichever is greater. The table applies that rule to common sizes.
| OD (mm) | OD tolerance (±mm) |
|---|---|
| 12.7 | 0.50 |
| 19.05 | 0.50 |
| 25.4 | 0.50 |
| 31.75 | 0.50 |
| 38.1 | 0.50 |
| 50.8 | 0.51 |
| 63.5 | 0.64 |
| 76.2 | 0.76 |
| 88.9 | 0.89 |
| 101.6 | 1.02 |
Wall tolerance follows the product standard and the wall thickness ordered. Tell us if you need a tighter OD for a fit, and we will advise on cold sizing.
Alloy Steel Welded Tubes Common Materials
The most commonly requested materials for Alloy Steel Welded Tubes are selected according to temperature, pressure, corrosion conditions, and mechanical requirements. A reliable Alloy Steel Welded Tubes Manufacturer can supply these materials in different sizes and specifications for industrial applications.
ASTM A334 Grade 3: 3.5% nickel steel (UNS K31918), suitable for low-temperature tube service.
ASTM A334 Grade 7: 2.5% nickel steel (UNS K21903), used for economical cold-service applications.
ASTM A334 Grade 9: Copper-nickel steel (UNS K22035), suitable for low-temperature service.
ASTM A423 Grades 1 & 2: Copper-chromium-nickel steel offering improved resistance to atmospheric corrosion.
16Mo3 (1.5415): Molybdenum alloy steel commonly used for pressure tubes at moderate temperatures.
AISI 4130: Chrome-moly steel (UNS G41300) used for frames, structural components, and machined parts.
AISI 4140: Higher-carbon chrome-moly steel (UNS G41400), commonly selected for shafts, sleeves, and heavy-duty components.
Alloy Steel Welded Tubes We Manufacture and Supply
We make Alloy Steel Welded Tubes in four product groups. Each one is built around a different job.
| Group | Use | Grades | Standard |
|---|---|---|---|
| Cold-service tubes | Refrigeration and low-temperature lines | A334 Gr 3, 7, 9 | ASTM A334 |
| Weathering tubes | Outdoor structures and frames | A423 Gr 1, 2 | ASTM A423 |
| Pressure tubes | Warm service lines | 16Mo3 | EN 10217-2 |
| Mechanical tubes | Machined parts, cylinders, frames | 4130, 4140 | ASTM A513, EN 10296-1 |
Applications of Alloy Steel Welded Tubes
- Refrigeration and cold storage: Brine, ammonia and refrigerant lines in A334 tubes.
- Oil and gas: Low-temperature instrument and process tubing.
- Petrochemical and chemical plants: Heat exchanger tubes and utility lines at moderate duty.
- Power generation: Feedwater and low-pressure heater tubes in 16Mo3.
- Marine: Structural and deck tubing where toughness matters.
- Pharmaceutical plants: Utility and chilled-water tubing outside the product-contact zone.
- Construction and EPC: Weathering tubes for frames, supports and outdoor structures.
- OEM and engineering: Hydraulic cylinders, shafts and machine frames from 4130 and 4140.
Why Choose Us as Your Alloy Steel Welded Tubes Manufacturer in India?
With 20+ years of experience since 2005, We have the expertise to manufacture Alloy Steel Welded Tubes in a wide range of grades, sizes, wall thicknesses, and lengths. We can supply commonly required grades such as ASTM A334 Gr. 3, Gr. 7, Gr. 9, ASTM A423 Gr. 1 & 2, 16Mo3, AISI 4130, and AISI 4140, with sizes manufactured as per applicable specifications and customer requirements. Our capabilities cover tubes for oil & gas, petrochemical, power, chemical, engineering, and other industrial applications.
We can handle production requirements of up to 100 tons per month, including bulk and project orders. Tubes can be supplied with EN 10204 3.1 Material Test Certificates (MTC), inspection reports, chemical and mechanical test reports, dimensional inspection reports, and other quality documents as required. As an experienced Alloy Steel Welded Tubes Supplier in India, we also provide suitable packaging, export documentation, and shipment support for customers across international markets.
Countries We Export Alloy Steel Welded Tubes To
We supply and export Alloy Steel Welded Tubes to customers across multiple international markets. Our export experience enables us to support distributors, stockists, EPC contractors, fabricators, and industrial buyers with standard, bulk, and project-based requirements.
North America: United States, Canada, Mexico
Middle East: UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain
Europe: UK, Germany, France, Italy, Netherlands, Spain
Asia Pacific: Australia, Singapore, Malaysia, Indonesia, Thailand, Vietnam
Africa: South Africa, Egypt, Nigeria, Kenya, Algeria
South America: Brazil, Argentina, Chile, Peru, Colombia
We support international orders with appropriate export packaging, material certificates, inspection documentation, and shipping coordination, helping ensure Alloy Steel Welded Tubes reach customers safely and according to their specified requirements.
Alloy Steel Welded Tubes FAQs
Common questions about alloy steel welded tube grades, dimensions, testing, tolerances, and supply.
Which grade of Alloy Steel Welded Tubes suits low-temperature service?
ASTM A334 Grade 3 is the usual pick near −100°C. Grade 7 works to about the same test temperature at lower alloy content, and Grade 9 suits milder cold down to −73°C.
Is welded tube better than seamless tube?
It depends on the job. Welded tube costs less and has a very even wall, so it is a good fit for cold service and machined parts. Seamless is better for the highest pressures and temperatures.
Can welded alloy tubes handle pressure?
Yes, within the design code. Codes such as ASME B31.3 apply a weld joint factor to welded tube, so allowable pressure can be lower than for seamless tube of the same size. Your designer should check it against your duty.
Is the weld seam heat treated?
Yes. Heat treatment after welding refines the seam, so the weld zone matches the tube body in strength and toughness.
How should I weld or bend these tubes on site?
Use a filler metal that matches the grade and a low-hydrogen process, and follow your welding procedure. Nickel and chrome-moly steels may need preheat. For tight bends, ask us about the right grade and wall.
What tolerances can I expect?
They follow the standard on your order. For EN 10217-2, OD varies by ±1% or ±0.5 mm, whichever is greater. For a tighter fit, ask us about cold sizing.
What sizes can I order?
The chart above shows OD 12.7 to 101.6 mm in 1.6 to 3.2 mm walls. Other sizes and walls can be quoted on request.
How do I work out the weight of an order?
Apply Weight (kg/m) = (OD − Wall) × Wall × 0.02466, with OD and wall in mm. Multiply by total length. Actual weight shifts slightly with wall tolerance.
What drives the price of Alloy Steel Welded Tubes?
Grade is the main driver, because nickel and chromium prices move the cost. Wall, OD, finish, quantity, impact testing, inspection and freight also count.
Which certificates come with the tubes?
Each order carries an EN 10204 3.1 certificate showing chemistry and mechanical results. A 3.2 certificate and third-party inspection are available on request.
Are impact tests done on the tubes?
For low-temperature grades such as A334, yes, at the test temperature the standard sets for the grade. Tell us the grade and temperature when you enquire.
Do you manufacture these tubes or only supply them?
We do both. Production is near Mumbai, and ready stock of popular sizes is supplied from the same location, subject to availability.
Can I get boiler chrome-moly grades such as T11 or T22 as welded tube?
Those grades fall under ASTM A213, which covers seamless tubes only. For boiler duty in chrome-moly, choose seamless. For cold or moderate service, welded tube is the better fit.
Do you export Alloy Steel Welded Tubes, and how are they packed?
Yes. We ship to 85+ countries from our Mumbai export office, and we pack the tubes to suit sea or air freight and your project needs.