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TORICH INTERNATIONAL LIMITED

  • China,Ningbo ,Zhejiang
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China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder
China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder

  1. China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder
  2. China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder
  3. China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder
  4. China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder
  5. China JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder

JIS G3429 STH12 Alloy Seamless Steel Tubes For High Pressure Gas Cylinder

  1. MOQ: 1 Tons
  2. Price: 800-1000 USD/Tons
  3. Get Latest Price
Payment Terms L/C, D/A, D/P, T/T, Western Union, MoneyGram
Supply Ability 60000 Ton/Tons per Year
Delivery Time 20-30days upon products
Packaging Details In bundles or in wooden boxes.
Grade STH11 STH12 STH21 STH22 STH31
Alloy or not Is Alloy
Technique Hot Rolled,Cold Drawn
Thickness 0.5 - 20 mm
Application Structure Pipe
Standard ASTM,GB,BS,DIN,JIS
Special pipe Thick Wall Pipe,precision steel tube
Section shape Round,Square,Rectangular or Square,Square/Rectangular
Secondary or not Non-secondary
Outer diameter(round) 114 - 610 mm
Length 1-12m,6m-12m or customed
Surface Customers't Requirement
Usage High Pressure Gas Cylinder
Brand Name TORICH
Model Number JIS G3429 STH12
Certification ISO9001, ISO14001, TS16949
Place of Origin Zhejiang/China

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  1. Product Details
  2. Company Details

Product Specification

Payment Terms L/C, D/A, D/P, T/T, Western Union, MoneyGram Supply Ability 60000 Ton/Tons per Year
Delivery Time 20-30days upon products Packaging Details In bundles or in wooden boxes.
Grade STH11 STH12 STH21 STH22 STH31 Alloy or not Is Alloy
Technique Hot Rolled,Cold Drawn Thickness 0.5 - 20 mm
Application Structure Pipe Standard ASTM,GB,BS,DIN,JIS
Special pipe Thick Wall Pipe,precision steel tube Section shape Round,Square,Rectangular or Square,Square/Rectangular
Secondary or not Non-secondary Outer diameter(round) 114 - 610 mm
Length 1-12m,6m-12m or customed Surface Customers't Requirement
Usage High Pressure Gas Cylinder Brand Name TORICH
Model Number JIS G3429 STH12 Certification ISO9001, ISO14001, TS16949
Place of Origin Zhejiang/China

JIS G3429 STH12 Alloy Seamless Steel Tubes for High Pressure Gas Cylinder

Material

STH12 is a seamless gas-cylinder tube grade under JIS G3429, widely used as the base tube for manufacturing high-pressure steel gas cylinders. It belongs to the C–Mn (manganese steel) family, balancing strength, ductility, and forming performance for cylinder body processing.

Specifications

  • Standard: JIS G3429 (Seamless steel tubes for high pressure gas cylinders)

  • Tube type: Seamless; hot-finished or cold-finished (marking commonly shown as -S-H / -S-C)

  • Typical size range (industry supply):

    • OD: 19.05–114.3 mm

    • WT: 2.0–14 mm

    • Length: up to 16,000 mm

  • Typical tolerances (commonly used for cylinder tube supply): OD ±1%, WT +30% (project-specific agreement recommended)

Main Features

  • Seamless structure (no weld seam), designed for pressure-bearing cylinder bodies.

  • Controlled chemistry suitable for forming, heat treatment planning, and stable performance batch-to-batch.

  • Safety-focused inspection basis: hydrostatic testing and/or NDT routes can be specified per order.

Our Advantages

  1. “How do you ensure the tube truly meets JIS G3429 chemistry?”
    We control heat chemistry to the JIS G3429 composition window and provide traceable heat/lot identification and inspection documentation aligned with JIS delivery practice.

  2. “Can you guarantee pressure integrity (leak-free)?”
    JIS G3429 allows hydrostatic testing; unless a higher pressure is specified by the buyer, the standard uses 5 MPa as the minimum hydrostatic pressure basis and requires no leakage.

  3. “Do you support ultrasonic / eddy-current NDT for internal and surface defects?”
    NDT can be specified using ultrasonic or eddy-current routes, and alternative equivalent NDT can be agreed when required by the project or local regulation.

  4. “What about surface quality and repair policy?”
    Tubes must have good internal/external surface finish with no harmful defects; surface dressing is permitted within thickness tolerance, while weld repair is not allowed—a key point for cylinder safety.

  5. “Will every tube be traceable and properly marked?”
    Marking can include grade, manufacturing method symbol (hot/cold finish), dimensions, and manufacturer ID to support full traceability through cylinder forming and testing.

Chemical Composition 

Unit: wt.% (heat analysis)

Grade C Si Mn P (max) S (max) Ni Cr Mo
STH11     ≤0.50 0.10–0.35 ≤1.80 ≤0.035 ≤0.035      
STH12 0.30–0.41    0.10–0.35    1.35–1.70    ≤0.030    ≤0.030         
STH21 0.25–0.35 0.15–0.35 0.40–0.90 ≤0.030 ≤0.030 ≤0.25 0.80–1.20    0.15–0.30   
STH22 0.33–0.38 0.15–0.35 0.40–0.90 ≤0.030 ≤0.030 ≤0.25 0.80–1.20 0.15–0.30
STH31 0.35–0.40 0.10–0.50 1.20–1.50 ≤0.030 ≤0.030 0.50–1.00    0.30–0.60 0.15–0.25

Mechanical Properties 

Grade  Yield Strength (MPa) Tensile Strength (MPa) Elongation (%)
STH11         ≥245 ≥410 ≥20
STH12 ≥315 ≥480 ≥18
STH21 ≥355 ≥550 ≥20
STH22 ≥410 ≥590 ≥18
STH31 345 540–640 16

Execution Standards (Common Options by System)

  • JIS: JIS G3429 (material tube for cylinders); cylinders referenced by JIS B 8230 / JIS B 8241

  • ASTM: ASTM A519 (seamless mechanical tubing, often used for cylinder-related tubing projects); ASTM A372 is also commonly referenced in cylinder supply chains depending on scope and jurisdiction.

  • EN / ISO (widely used in Europe & international transport tube systems): EN ISO 11120 / ISO 11120 (refillable seamless steel tubes for compressed gas transport systems); EN 10216 / EN 10297 are often used for pressure-purpose / engineering seamless tubes when specified.

  • GOST: GOST 8732-78 (hot-deformed seamless steel pipes) and related seamless pipe standards as specified by project documentation.

  • GB: GB/T 18248-2021 (Seamless steel tubes for gas cylinder).

Application Areas

High-pressure gas containment and transport, especially where seamless integrity and traceability are mandatory.

Typical where-used examples:

  • Industrial gas cylinders: oxygen, nitrogen, argon, CO₂ shielding gas for welding/cutting.

  • Medical cylinders: medical oxygen cylinder bodies and related high-pressure containers.

  • Energy & mobility: CNG cylinders / high-pressure storage cylinders (project-specific grade selection required).

  • Chemical & specialty gases: high-purity or reactive gases requiring reliable cylinder shells.

 

     

 

     

 

Q: Are you trading company or manufacturer ?

A: manufacturer,also can do trading.

 

Q: How long is your delivery time?

A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock, it is according to quantity.

 

Q: Do you provide samples? is it free or extra ?

A: Yes, we could offer the sample for free charge but need pay the cost of freight.

 

Q: What is your terms of payment ?

A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.

If you have another question, pls feel free to contact with me.

Company Details

Bronze Gleitlager

,

Bronze Sleeve Bushings

 and 

Graphite Plugged Bushings

 from Quality China Factory
  • Business Type:

    Manufacturer,Distributor/Wholesaler,Exporter,Trading Company,Seller

  • Year Established:

    1997

  • Total Annual:

    10million-15million

  • Employee Number:

    100~150

  • Ecer Certification:

    Verified Supplier

Who We are ? TORICH is an enterprise that has been producing precision steel pipes and steel pipe processing for over 20 years, with a factory area of approximately 20000 square meters   The main products produced are carbon steel and alloy steel grade seamless steel pipes, we... Who We are ? TORICH is an enterprise that has been producing precision steel pipes and steel pipe processing for over 20 years, with a factory area of approximately 20000 square meters   The main products produced are carbon steel and alloy steel grade seamless steel pipes, we...

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Get in touch with us

  • Reach Us
  • TORICH INTERNATIONAL LIMITED
  • Suite 1604-3, Hongan Plaza, #258 Die Yuan Road, Yinzhou District, Ningbo City, China
  • https://www.precisionsteeltube.com/

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