STKM11A ERW Carbon Steel Welded Pipe Precision Automotive Steel Tube

Material

Electric-Resistance Welded (ERW) low-carbon steel tubing manufactured to JIS G3445 STKM11A and supplied as precision, cold-sized round tubes for automotive and machinery applications. Typical forming includes bending, flaring, flanging and flattening with consistent surface and weld integrity per precision-tube standards.

Specifications

• Process: ERW (high-frequency), cold sizing; optional annealed (+A) or normalized (+N) after sizing.

• Supply conditions: +CR1 / +CR2 (as-welded & cold-sized), +A (soft annealed), +N (normalized) to match downstream forming needs.

• Standards typically matched: JIS G3445 (STKM series), EN 10305-3 (E-grades), ASTM A513 (Types 1/2 mechanical tubing), GB/T 13793 (ERW steel pipe).

Key Features

• Automotive-grade precision: Tight OD/WT tolerances and specified maximum surface roughness per EN 10305-3 for precision tubes.

• Formability & weldability: Low carbon (C ≤0.12%) and Mn ≤0.60% promote easy bending and flaring with stable weldability.

• Consistent weld seam quality: Flash-in/flash-out control available; internal flash controlled to ≤0.005 in (≈0.13 mm) when specified.

• Verified straightness: Meets typical ASTM A513 straightness criteria 1/32 in per 3 ft (~0.8 mm/m); tighter options available by agreement.

• Optional heat treatment windows: +A for maximum ductility; +N for balanced strength/ductility; +CR1/+CR2 when higher as-welded strength is desired.

Chemical Composition

Mechanical Properties

Governing Standards

• JIS: JIS G3445 (STKM11A/12A/12C) carbon steel tubes for machine structure.

• EN: EN 10305-3 (E155/E190/E195) welded, cold-sized precision tubes; precision tolerances and surface roughness defined; typical field—automotive.

• ASTM/ASME: ASTM/ASME A513 (Types 1 & 2) ERW carbon steel mechanical tubing with specific OD/WT/straightness tolerances; flash control options.

• GB (China): GB/T 13793 ERW steel pipe (general); precision applications often align with EN 10305-3 requirements on request.

• GOST (Russia): GOST 10705/10704 welded steel pipes (general-purpose baselines) used for referencing dimensional tolerances in CIS markets.

Application Fields

General: Automotive, machinery, furniture, appliances, bicycles, and general engineering precision tubing.

Automotive examples (where it is used within the system):

• Chassis & body: seat structures, cross-members, crash-bracing.

• Steering & suspension: steering columns/shafts, shock absorber shells, stabilizer bar sleeves.

• Powertrain & fuel: fuel rails, EV battery pack frames, coolant lines (with post-coating).

• Interior mechanisms: slider rails, hinge arms.

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.

Who We are ?

-------A professional steel pipes materials inventor, manufacturer and solution provider
Torich International Limited is a professional manufacturer and exporter of steel pipes materials. It is an international marketing and sales company specialized in steel tubes, which holds the factories of Seamless Steel Tubes with Carbon and Alloy Steel Grade, Welded Precision Steel Tubes,DOM Steel Tubes, Seamless & Welded Stainless Steel Tubes with Nickel and Alloy Steel Grade.
Our factory was established since 1997, with the name of TORICH INTERNATIONAL LIMITED. The factories’ technicians are of great engineering experience in steel pipe industry for more than 20 years, which are in great command of production technology for Cold Drawing and Cold Rolling. So we have strong technician team and manufacturing capability.

What products we do?

------- Invent and produce various Precision Steel Pipes

Our steel pipes cover the following ranges:
Seamless Precision Steel Pipes

Bearing Steel Tubes
Welded Precision Steel Pipes, with DOM production
Seamless Heat Exchanger Steel Pipe
Seamless Boiler Steel Pipes

Honed Tubes

Hydraulic Cylinder Steel Tubes

Hydraulic Telescopic Cylinder Tubes
Seamless Structural Steel Pipes
Seamless Mechanical Steel Pipes
Seamless Alloy Steel Tubes & Pipes
Seamless Stainless Steel tubes
Welded Stainless Steel Tubes
Seamless Stainless Steel Tubes & Pipes
Welded Stainless Steel Tubes & Pipes
Seamless Carbon Steel Tubes & Pipes
Nickel Alloy Steel Tubes & Pipes

What TORICH do:
1. Producing Steel Tubes
2. Selling both on Domestic and International Market
3. Precisely Targeting Customers’ Requirement- Sourcing the right factory for right products for Customers

Products Application:
Oil Cylinders
Air Cylinder, 
Automotive Cylinder Liners
Boilers, Pressure Vessels
Shell & Heat Exchangers
Jack Lifting
Telescopic Systems
Pneumatic Cylinders
Agricultural Machineries

Size range is: 
O.D. 4-350mm, 
W.T. 0.5-30mm, 
Length: according to customer’s requirement and agreement
 

Steel Grade:
Carbon Steel Grade:
ST35.8, ST37.0, ST44, ST52;
E155, E195, E215, E235, E275, E355;
195GH, P235GH, P265GH, P195TR1, P195TR2, P235TR1, P235TR2, P265TR1, P265TR2;
SAE1010, SAE1020, SAE1026, SAE1035, SAE1045;

Carbon steel tube: SA178, A179, A192, A210, SA213, SA214, etc.
Alloy Steel Grade:
T2, T5, T9, T11, T12, T17, T21, T22, T91,T92, 15Mo3,16Mo3, 13CrMo44;
SAE4130, SAE4140, 40Cr, 40Cr4, 10CrMo910, 12CrMo910, 11CrMo910,
25CrMo4, 35CrMo, 35CrMo4, 42CrMo4, 34CrMo4, 20MnV, 20MnV6,20CrMn;
Carbon steel tube: A179,A192,A210,DIN17175,etc.

Bearing Steel Grades:
GCr15 52100 suj2 suj3 100Cr6 SKF3S SKF3S 20CrNiMo 8620H 4118H;

Nickel Alloy Grade:
N02200/2201, N04400, N06600, N06601, N06625, N06852, N06219, N06690, N08800/8810/8811, N08825, N08028, N08535, N08904, N08925, N08926, N010276, N06022, etc.

Austenitic/Super Austenitic Stainless Steel Grade:
304/304L, 316/316L, 314, 321, 347H, 316Ti, 316LMod, 317L/N, 310S, 253MA, 330, 904L, S31254, XM-19, etc. 

Ferrite/Martensite Stainless Steel Grade:
TP410, TP405, TP420, TP430, TP430Ti, TP403, TP409, TP444, TP439, TP446, etc. 

Duplex/Super Duplex Stainless Steel Grade:
S31803, S32304, S31500, S32550, S32750, S32760, etc. 
Corporate Culture:
We focus on Quality First, Quality Traceability, and Quality Stability!
We focus on Customer First, People First, and Quality-Oriented!
Success:
First factory started in 1997, in the name of Torich , now covers 50000 square meters of factory building, with more than 100employees, and over 45 million RBM assets.
In 2008, we started the company of Torich International Limited for international business and marketing.
Welcome partners from all over the world for long term cooperation!