JIS3445 Carbon Steel Tube for Auto Exhaust System
Typical fields of application are in:
Automobile and motorcycle Shock Absorber Pipe
Mechanical steel pipes for auto and motor parts
Gas Spring pipe
motor Casing Pipe etc
size:length--2~12m WT--2~5mm OD--10-20mm
material:STKM11A, STKM12(A/B/C). etc.
Production process: ordinary high-frequency welded pipe
Advantages: small diameter and thick wall
Surface Quality:The internal and external surfaces of the steel tube are not allowed to
have cracks, scabs, folds, delaminations, laps, and burns. Allows for scribes, scratches,
misalignment of welds, burns, oxide scales, and external burr removal traces that are not
more than a negative wall thickness deviation.
Inspection items:
chemical composition
Tensile test
Ultrasonic examination
Eddy current flaw detection
Bending test
Flattening test
Permissible Tolerance of Outer Diameter and Wall Thickness (mm)
| Type of steel Tube | Dimension of steel tube | Permissible tolerance |
| Average class | High class |
| Hot-rolled (extruded and expanded) tube | Outer diameter D | All | ±1%
(min.+/-0.50) | - |
| Wall thickness | All | +15%/-12.5%
(min.+4.5/-4.0) | - |
| Cold-drawn (cold-rolled) tube | Outer diameter D | 6~10 | ±0.2 | ±0.15 |
| >10~30 | ±0.40 | ±0.20 |
| >30~50 | ±0.45 | ±0.30 |
| >50 | ±1% | ±0.8% |
| Wall thickness | <1 | ±0.15 | ±0.12 |
| >1~3 | +15%
-10% | +12.5%
-10% |
| >3 | +12.5%
-10% | ±10% |
| Note: For hot-expanded tubes with outer diameter>35mm,the permissible tolerance of wall thickness is±18%. |
Longitudinal Mechanical Properties of Steel Tubes
| NO. | Steel Grade | Tensile Strength(Mpa) | Yield point(Mpa) | Elongation after breaking(%) |
| s<16 | s>16 |
| Not less than |
| 1 | 10 | 335~475 | 205 | 195 | 24 |
| 2 | 20 | 410~550 | 245 | 235 | 20 |
| 3 | Q295 | 430~610 | 295 | 285 | 22 |
| 4 | Q345 | 490~665 | 325 | 315 | 21 |
Permissible deviations of the product analysis from the specified limits
| Element | Limiting values for cast analysis | Permissible deviatioon of the product analysis in % by mass |
| C | ≤0.22 | +0.02 |
| Si | ≤0.55 | +0.05 |
| Mn | ≤1.60 | +0.10 |
| P | ≤0.025 | +0.005 |
| S | ≤0.015 | +0.003 |
| Al | ≥0.025 | -0.005 |
What is your Guarantee?
1.SO9001:2008 and TS16949 certification, SGS, BV, TUV or other third party inspection is available.
2.High quality with competitive price.
3.Advanced technology, experienced engineer, ISO quality system for quality assurance and traceability.
Do you have agent or distributor in our country?
1.We are recruiting area agent and distributor all over the world, welcome to send us your
mail or call us for detail discussion.
How is your production capability?
1.2000 tons monthly production capacity, 5000 tons monthly trading capability
2.Prompt and Timely shipment
How to get the sample?
1.You are requested to pay for sample charges and courier charges from China to your country;
and the free sample is according the product like size, steel grade and quantity, please consult
our sales for details
2.Sample charges will be refunded when order is placed.
What is your Payment Term?
1.T/T: 30% deposit in advance, the balance 70% paid before shipment
2.30% down payment, the balance 70% paid against L/C at sight
3.Upon negotiation
Who are your customers?
1.Stockists, Distributors,Wholesalors,Agents, Traders, End Users, etc
How long will you react on our requirement?
1.Your requirement would be treated within 24 hours on weekdays.
Quotations would be sent upon technical details confirmed by customer!
JIS3445 Carbon Steel Tube for Auto Exhaust Syste
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