Precision ERW Carbon Steel Pipe with 20-426mm Outer Diameter 0.4-100mm Thickness and 1-12m Length for Automotive Applications
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
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Process: ERW (high-frequency), cold sizing; optional annealed (+A) or normalized (+N) after sizing.
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Supply conditions: +CR1 / +CR2 (as-welded & cold-sized), +A (soft annealed), +N (normalized) to match downstream forming needs.
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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
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Automotive-grade precision: Tight OD/WT tolerances and specified maximum surface roughness per EN 10305-3 for precision tubes.
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Formability & weldability: Low carbon (C ≤0.12%) and Mn ≤0.60% promote easy bending and flaring with stable weldability.
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Consistent weld seam quality: Flash-in/flash-out control available; internal flash controlled to ≤0.005 in (≈0.13 mm) when specified.
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Verified straightness: Meets typical ASTM A513 straightness criteria 1/32 in per 3 ft (~0.8 mm/m); tighter options available by agreement.
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Optional heat treatment windows: +A for maximum ductility; +N for balanced strength/ductility; +CR1/+CR2 when higher as-welded strength is desired.
Chemical Composition
| Grade / Standard | C | Si | Mn | P | S | Al (min) |
|---|---|---|---|---|---|---|
| STKM11A (JIS G3445) | ≤0.12 | ≤0.35 | ≤0.60 | ≤0.040 | ≤0.040 | — |
| E155 (EN 10305-3) | ≤0.11 | ≤0.35 | ≤0.70 | ≤0.025 | ≤0.025 | ≥0.015 |
| E190 (EN 10305-3) | ≤0.10 | ≤0.35 | ≤0.70 | ≤0.025 | ≤0.025 | ≥0.015 |
| E195 (EN 10305-3) | ≤0.15 | ≤0.35 | ≤0.70 | ≤0.025 | ≤0.025 | — |
| 1010 (ASTM A513 ref.) | 0.08–0.13 | — | 0.30–0.60 | ≤0.035 | ≤0.035 | — |
Mechanical Properties
| Grade | Condition | Yield (MPa) | Tensile (MPa) | Elongation (%) |
|---|---|---|---|---|
| STKM11A (JIS) | As specified for tubes | — | ≥290 | ≥35 (L); ≥30 (T) |
| E155 (EN 10305-3) | +N | ≥155 (ReH) | 270–410 | ≥28 |
| E190 (EN 10305-3) | +CR2 | ≥190 (ReH) | ≥270 | ≥26 |
| E195 (EN 10305-3) | +N (typical) | ≥195 (ReH) | ~320–510 | ≥28 (typical) |
| STKM12A (JIS) | Tubes | ≥175 | ≥340 | ≥35 (L); ≥30 (T) |
Governing Standards
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JIS: JIS G3445 (STKM11A/12A/12C) carbon steel tubes for machine structure.
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EN: EN 10305-3 (E155/E190/E195) welded, cold-sized precision tubes; precision tolerances and surface roughness defined; typical field—automotive.
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ASTM/ASME: ASTM/ASME A513 (Types 1 & 2) ERW carbon steel mechanical tubing with specific OD/WT/straightness tolerances; flash control options.
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GB (China): GB/T 13793 ERW steel pipe (general); precision applications often align with EN 10305-3 requirements on request.
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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):
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Chassis & body: seat structures, cross-members, crash-bracing.
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Steering & suspension: steering columns/shafts, shock absorber shells, stabilizer bar sleeves.
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Powertrain & fuel: fuel rails, EV battery pack frames, coolant lines (with post-coating).
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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.
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