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Stainless Steel Seamless Pipes and Tubes Manufacturer in India
MLTI Private Limited (formerly Moonlight Tube Industries) is a stainless steel seamless pipes and tubes manufacturer, supplier and exporter based in Gujarat, India, operating a works with a total rated capacity of about 8,000 MT per year
Seamless product begins as a solid billet, pierced and drawn to finished size, so the wall carries no longitudinal weld. Seamless SS Pipe is certified to ASTM A312 / ASME SA-312 with dimensions to ASME B36.19M. Seamless tube follows ASTM A213 / ASME SA-213 for boiler and heat exchanger duty, and ASTM A269 for general service tubing. We manufacture eleven austenitic grades, including 304, 304L, 310, 316, 316L, 316Ti, 321, 321H, 347, 347H, and 904L. Chromium between 16.0 and 26.0% forms the passive film, and nickel between 8.0 and 28.0% holds the austenitic structure. Certified minimums stand at 515 MPa tensile and 205 MPa yield strength, easing to 485 MPa and 170 MPa on the low-carbon L grades, with 35% elongation throughout. Grade 904L sits apart at 490 MPa tensile and 215 MPa yield, while seamless 321 pipe falls to 485 MPa tensile and 170 MPa yield, and seamless 321H pipe to 480 MPa tensile and 170 MPa yield, above 9.5 mm wall; tube to SA-213 carries no such reduction.
As a dedicated stainless steel seamless pipes and tubes manufacturer and supplier, we cover 1/8 inch to 10 inch NB in SCH 5S, 10S, 40S and 80S, with ready stock held on selected standard sizes and grades and the balance manufactured to order. Processing facilities dimension tubing strictly by outside diameter and wall thickness. Refineries, chemical plants, and power facilities specify these products for high-pressure duty. We hold ISO 14001 and ISO 45001 certifications and approvals under BIS, EIL, IBR, and PED standards; every single shipment includes an EN 10204 3.1 inspection certificate.
Seamless Stainless Steel Pipe and Tube Specifications
The specifications of SS seamless pipes and tubes, with all applicable standards, are given in the table below.
| Parameter | Value |
|---|---|
| Grades | 304, 304L, 310, 316, 316L, 316Ti, 321, 321H, 347, 347H, 904L |
| Applicable standards | ASTM A312: Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes ASTM A213: Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes ASTM A269: Seamless and Welded Austenitic Stainless Steel Tubing for General Service |
| Dimensional Standards | Pipe: ASME B36.19M (NB and schedule). Tube: ordered outside diameter and wall thickness per ASTM A213 / ASTM A269. |
| Pipe size | 1/8 inch NB (6 mm) to 10 inch NB (250 mm) |
| Schedule | SCH 5S, SCH 10S, SCH 40S and SCH 80S across the full range; SCH 20S intermediate wall on request |
| Pipe wall thickness | 1.24 mm to 12.70 mm, by bore and schedule |
| Tube size | Ordered by outside diameter and wall thickness |
| Manufacturing process | Seamless: pierced billet, cold drawn, solution annealed |
| Length | Cut lengths as required, up to 6 metres standard |
| End type | Plain end; bevelled on request |
| Finish | Mill finish, pickled and passivated; polished to order |
Stainless Steel Seamless Pipes and Tubes Grades
Eleven grades of SS seamless pipe and tube leave this works, separated by carbon content, molybdenum addition and the stabilising element present.
Seamless Stainless Steel Pipe and Tubes Forms
Round, square and rectangular hollows start as a pierced billet. Only the round exits that way. Square and rectangular forms come off a redraw die that reshapes the round hollow.
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Rectangular
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Round Stainless Steel Seamless Pipe
SS Seamless Pipe & Tube Dimensions Chart
This reference section outlines standard wall thickness schedules, outer diameters, and linear weights per meter for stainless steel seamless pipes and tubes across global sizes.
SS seamless pipe size chart:
| Nominal Bore (mm) | Inch | Outside Diameter (mm) | Sch-5S (mm) | Sch-10S (mm) | Sch-20S (mm) | Sch-40S (mm) | Sch-80S (mm) |
|---|---|---|---|---|---|---|---|
| 6 | 1/8 | 10.30 | 1.24 | 1.24 | 1.50 | 1.73 | 2.41 |
| 8 | 1/4 | 13.70 | 1.24 | 1.65 | 2.00 | 2.24 | 3.02 |
| 10 | 3/8 | 17.10 | 1.24 | 1.65 | 2.00 | 2.31 | 3.20 |
| 15 | 1/2 | 21.34 | 1.65 | 2.11 | 2.30 | 2.77 | 3.75 |
| 20 | 3/4 | 26.70 | 1.65 | 2.11 | 2.55 | 2.87 | 3.91 |
| 25 | 1 | 33.40 | 1.65 | 2.77 | 3.00 | 3.38 | 4.55 |
| 32 | 1 1/4 | 42.20 | 1.65 | 2.77 | 3.00 | 3.56 | 4.85 |
| 40 | 1 1/2 | 48.30 | 1.65 | 2.77 | 3.00 | 3.68 | 5.08 |
| 50 | 2 | 60.30 | 1.65 | 2.77 | 3.00 | 3.91 | 5.54 |
| 65 | 2 1/2 | 73.00 | 2.11 | 3.05 | 4.00 | 5.16 | 7.01 |
| 80 | 3 | 88.90 | 2.11 | 3.05 | 4.00 | 5.49 | 7.62 |
| 100 | 4 | 114.30 | 2.11 | 3.05 | 4.50 | 6.02 | 8.56 |
| 125 | 5 | 141.30 | 2.77 | 3.40 | 5.00 | 6.55 | 9.53 |
| 150 | 6 | 168.30 | 2.77 | 3.40 | 6.35 | 7.11 | 10.97 |
| 200 | 8 | 219.10 | 2.77 | 3.76 | 6.35 | 8.18 | 12.70 |
| 250 | 10 | 273.10 | 3.40 | 4.19 | 6.35 | 9.27 | 12.70 |
SS pipes weight chart:
| Nominal Bore (mm) | Inch | Sch-5S Weight (kg/m) | Sch-10S Weight (kg/m) | Sch-20S Weight (kg/m) | Sch-40S Weight (kg/m) | Sch-80S Weight (kg/m) |
|---|---|---|---|---|---|---|
| 6 | 1/8 | 0.276 | 0.28 | 0.33 | 0.37 | 0.47 |
| 8 | 1/4 | 0.39 | 0.49 | 0.58 | 0.631 | 0.80 |
| 10 | 3/8 | 0.49 | 0.63 | 0.74 | 0.845 | 1.10 |
| 15 | 1/2 | 0.80 | 1.00 | 1.08 | 1.27 | 1.61 |
| 20 | 3/4 | 1.03 | 1.28 | 1.52 | 1.68 | 2.24 |
| 25 | 1 | 1.30 | 2.09 | 1.94 | 2.50 | 3.24 |
| 32 | 1 1/4 | 1.65 | 2.70 | 2.90 | 3.38 | 4.47 |
| 40 | 1 1/2 | 1.91 | 3.11 | 3.35 | 4.05 | 5.41 |
| 50 | 2 | 2.40 | 3.93 | 4.24 | 5.44 | 7.48 |
| 65 | 2 1/2 | 3.69 | 5.26 | 6.81 | 8.63 | 11.40 |
| 80 | 3 | 4.51 | 6.45 | 8.37 | 11.30 | 15.20 |
| 100 | 4 | 5.84 | 8.36 | 12.18 | 16.07 | 22.30 |
| 125 | 5 | 9.47 | 11.57 | 16.81 | 21.80 | 31.97 |
| 150 | 6 | 11.32 | 13.84 | 25.36 | 28.30 | 42.70 |
| 200 | 8 | 14.79 | 19.96 | 33.31 | 42.60 | 64.60 |
| 250 | 10 | 22.63 | 27.73 | 41.77 | 60.50 | 96.00 |
Seamless SS tubes size chart:
| Size | OD (mm) | 10 BWG - 3.40 mm Weight/MTR | 12 BWG - 2.77 mm Weight/MTR | 14 BWG - 2.11 mm Weight/MTR | 16 BWG - 1.65 mm Weight/MTR | 18 BWG - 1.25 mm Weight/MTR | 19 BWG - 1.07 mm Weight/MTR |
|---|---|---|---|---|---|---|---|
| 1/2" | 12.7 | 0.78 | 0.68 | 0.55 | 0.45 | 0.35 | 0.31 |
| 5/8" | 15.875 | 1.05 | 0.89 | 0.72 | 0.58 | 0.45 | 0.39 |
| 3/4" | 19.05 | 1.31 | 1.11 | 0.88 | 0.71 | 0.55 | 0.47 |
| 1" | 25.4 | 1.85 | 1.55 | 1.21 | 0.97 | 0.74 | 0.64 |
| 1 1/4" | 31.75 | 2.38 | 1.98 | 1.54 | 1.23 | 0.94 | 0.81 |
| 1 1/2" | 38.1 | 2.91 | 2.41 | 1.87 | 1.48 | 1.13 | 0.97 |
| 2" | 50.8 | 3.98 | 3.28 | 2.53 | 2.00 | 1.52 | 1.31 |
| 2 1/2" | 63.5 | 5.04 | 4.15 | 3.19 | 2.52 | 1.91 | 1.64 |
| 3" | 76.2 | 6.11 | 5.01 | 3.85 | 3.04 | 2.30 | 1.98 |
| 3 1/2" | 88.9 | 7.18 | 5.88 | 4.51 | 3.55 | 2.69 | 2.31 |
| 4" | 101.6 | 8.24 | 6.75 | 5.17 | 4.07 | 3.08 | 2.65 |
Seamless vs Welded Stainless Steel Pipes and Tubes
Choosing between seamless and welded stainless pipe comes down to matching the route to the job. Seamless suits pressure and cyclic loads; welded suits large bores at moderate duty. ASME B31.3 rates the two differently, and cost, concentricity, and mechanical minima diverge across grades.
| Parameter | Seamless | Welded |
|---|---|---|
| Best-suited service | High pressure, elevated temperature, cyclic loading | Large bore, moderate duty |
| Longitudinal seam | None | Present (fusion weld) |
| ASME B31.3 weld joint factor | 1.00 — full wall thickness counts in the pressure calculation | Derated unless the seam is radiographed |
| Cost per metre | Higher | Lower |
| Concentricity | Standard | Tighter |
| Chemical requirements (ASTM A312) | Identical | Identical |
| Mechanical minima — most grades | Match welded values | Match seamless values |
| Mechanical minima — Gr. 321 / 321H above 9.5 mm wall | Lower tensile and yield minima apply | Standard minima apply |
Stainless Steel Seamless Pipe and Tube Industrial Applications
Four sectors take the most seamless output, and each specifies the form for a different combination of pressure, temperature and corrosion.
Oil, Gas and Petrochemical
Hydrocarbon process headers, hydrogen service lines and exchanger circuits operate at pressures where a longitudinal seam is a liability. Grades 321 and 347 carry the hot sections, with 316 on condensate duty.
Chemical Processing Plants
Acid transfer lines and reactor connections meet chlorides and reducing acids. SS 316 seamless pipe covers most of this duty, and 904L is reserved for dilute sulphuric acid streams.
Pharmaceutical and Food Processing
Purified water loops and product contact lines favour a seamless bore, since no seam exists to hold residue through cleaning cycles. Grade 316L is the standard specification for contact duty.
Power Generation and Boiler Plant
Boiler, superheater and heat exchanger tubes to SA-213 sit at creep temperatures for years, so the stabilised grades 321H and 347H are specified there. IBR approval covers Indian boiler installations.
Water Treatment and Desalination
Desalination and municipal infrastructure drive rapid expansion in water treatment. Reverse osmosis and multi-stage flash plants deploy Grade 316L across main process water circuits. Grade 904L resists crevice corrosion in seawater heat exchanger bundles where chloride levels exceed 1,000 ppm.
Marine and Offshore
Offshore platforms, seawater cooling lines, and pump casings expose materials to high chloride levels that eliminate 304 stainless steel. Grade 316L prevents pitting and stress corrosion cracking in marine environments. Eliminating longitudinal welds, seamless piping removes the primary crevice corrosion target in aggressive saltwater circuits.
Pulp and Paper
Chlorine dioxide and hypochlorite bleaching circuits destroy Grade 304 within months. Grade 316 covers standard bleaching piping; 904L takes the most aggressive acidic effluent and high-chloride bleach streams.
Aerospace and Defence
Cold-drawn seamless tube meets the dimensional precision and surface quality that engine fuel lines, hydraulic systems, and landing gear components require under sustained mechanical and thermal load.
Stainless Steel Seamless Pipe and Tube Shipping and Packaging
Our SS seamless pipes and tubes are securely packaged, clearly stencilled, fully certified, and efficiently shipped across domestic and global markets.
- Lengths are bundled by grade, size and schedule, then packed in timber cases for sea freight.
- Plastic caps close both ends against ingress during transit.
- EN 10204 3.1 mill test certificates accompany the consignment documents.
- Export orders move on FOB or CFR terms to Brazil, Vietnam, Turkey and Europe.
Why Choose MLTI Private Limited?
Buyers return to Moonlight Tubes for certified material, approved grades and stock that ships on schedule. Every order is backed by documented quality, a wide size range and delivery commitments we hold to.
Quality Certification
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IBR & EIL Approved
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Why
Choose Us
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Wide Range of Grades & Sizes
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Timely Global Delivery
FAQs about SS Seamless Pipes and Tubes
Seamless SS pipe is the superior choice for critical high-pressure, high-temperature and cyclic fatigue duties because the pipe wall has no longitudinal weld seam. Welded pipe to the same ASTM A312 specification is more economical and serves well across general, low-to-moderate-pressure fluid transfer lines
Stainless steel seamless pipes and tubes fall under HS Code 7304. Specifically, cold-drawn or cold-rolled seamless products are classified under 7304.41, while hot-finished and other seamless stainless tubular profiles fall under 7304.49.
Yes. Every consignment is supplied with an EN 10204 3.1 mill test certificate (MTC) showing complete chemical analysis, mechanical testing data, and heat number traceability. Positive Material Identification (PMI) testing reports are also available upon request.
ASTM A269 covers seamless and welded austenitic stainless steel tubing for general corrosion resistance and utility service. For specialised pressurised equipment such as boilers, superheaters, and shell-and-tube heat exchangers ASTM A213 / ASME SA-213 is the standard specification used.