JIS G3445


JIS G3445 Steel Pipe

JIS G3445 is a Japanese standard that specifies the requirements for carbon steel tubes used in machinery, equipment, automobiles, bicycles, furniture, appliances, and other mechanical parts. These tubes are not just any regular tubes; they are meticulously designed for machine structural purposes. The seamless pipes under this standard are widely utilized in various industries, including nuclear devices, gas, petrochemical, shipbuilding, and boiler industries. The production process of these tubes ensures that they meet the highest standards set by the Japanese Industrial Standards (JIS), making them reliable and efficient for any mechanical application.

JIS G3445 Specification

Our JIS G3445 carbon steel tubes are available in various steel grades, dimensions, and production procedures. They come with different surface coatings, end types, and joint methods, and offer machining services. The manufacturing methods include Hot Finished Seamless, Cold Finished Seamless, ERW Steel Tube, and Butt-welded Steel Tube. With such diversity in production methods and specifications, we ensure that our clients receive products tailored to their specific needs.

Production StandardJIS3445
Manufacturing ProcessesBW ERW  SMLS
Outside DiameterDN25 – DN500
Wall Thickness3mm – 18mm
Pipe Lengthspecific
Steel GradeSTKM11A、STKM12(A,B,C)、STKM13(A,B,C)、STKM14(A,B,C),STKM15(A,C),STKM16(A,C),
Corrosion PreventionLacquer, Varnish, Oiling, Galvanizing
End ProcessesSquare Cut, Bevelling, Threading, Socket
Further ProcessingWelding, Bending, Hole Drilling, Punching, Swaging, Tapering, Flaring, Expanding

JIS G3445 Dimension Table


Our JIS G3445 tubes come in a range of outer diameters from 19.05mm to 630mm and wall thicknesses from 2.0mm to 14mm. Usually agreed between the purchaser and the manufacturer. With such a wide range of dimensions, we cater to various industries and applications, ensuring that our clients always find the perfect fit for their projects.

Chemical Requirements of JIS G3445

The chemical composition of our tubes is strictly controlled to ensure high-quality steel. Elements like carbon, silicon, manganese, sulfur, and phosphorus are kept within specified limits, ensuring the tubes’ durability and efficiency.

GradeSymbol of GradeCSiMnPSNb or V
Grade 11ASTKM11A0.12 max.0.35 max.0.60 max.0.040 max.0.040 max.
Grade 12ASTKM12A0.20 max.0.35 max.0.60 max.0.040 max.0.040 max.
Grade 13ASTKM13A0.25 max.0.35 max.0.30 to 0.900.040 max.0.040 max.
Grade 14ASTKM14A0.30 max.0.35 max.0.30 to 1.000.040 max.0.040 max.
Grade 15ASTKM15A0.25 to 0.350.35 max.0.30 to 1.000.040 max.0.040 max.
Grade 16ASTKM16A0.35 to 0.450.40 max.0.40 to 1.000.040 max.0.040 max.
Grade 17ASTKM17A0.45 to 0.550.40 max.0.40 to 1.000.040 max.0.040 max.
Grade 18ASTKM18A0.18 max.0.55 max.1.50 max.0.040 max.0.040 max.
Grade 19ASTKM19A0.25 max.0.55 max.1.50 max.0.040 max.0.040 max.
Grade 20ASTKM20A0.25 max.0.55 max.1.60 max.0.040 max.0.040 max.0.15 max.

Mechanical Requirements of JIS G3445

Our tubes are tested for their mechanical properties, ensuring they meet the required tensile strength, yield strength, and elongation percentages. This ensures that our tubes can withstand the toughest conditions and deliver optimal performance.

GradeSymbol of GradeTensile Strength N/mm2Yield Point or Proof Stress N/mm2Elongation %FlatteningBendability
No.11 Test Piece No.12 Test Piece,tube axis directionNo.Test Piece,perpendicular to tube axisDistance between flat platesBend AngleInside radius
Grade 11ASTKM11A290 min.35 min.30 min.1/2 D180°4 D
Grade 12ASTKM12A340 min.175 min.35 min.30 min.2/3 D90°6 D
BSTKM12B390 min.275 min.25 min.20 min.2/3 D90°6 D
CSTKM12C470 min.355 min.20 min.15 min.
Grade 13ASTKM13A370 min.215 min.30 min.25 min.2/3 D90°6 D
BSTKM13B440 min.305 min.20 min.15 min.3/4 D90°6 D
CSTKM13C510 min.380 min.15 min.10 min.
Grade 14ASTKM14A410 min.245 min.25 min.20 min.3/4 D90°6 D
BSTKM14B500 min.355 min.15 min.10 min.7/8 D90°8 D
CSTKM14C550 min.410 min.15 min.10 min.
Grade 15ASTKM15A470 min.275 min.22 min.17 min.3/4 D90°6 D
CSTKM15C580 min.430 min.12 min.7 min.
Grade 16ASTKM16A510 min.325 min.20 min.15 min.7/8 D90°8 D
CSTKM16C620 min.460 min.12 min.7 min.
Grade 17ASTKM17A550 min.345 min.20 min.15 min.7/8 D90°8 D
CSTKM17C650 min.480 min.10 min.5 min.
Grade 18ASTKM18A440 min.275 min.25 min.20 min.7/8 D90°6 D
BSTKM18B490 min.315 min.23 min.18 min.7/8 D90°8 D
CSTKM18C510 min.380 min.15 min.10 min.
Grade 19ASTKM19A490 min.315 min.23 min.18 min.7/8 D90°6 D
CSTKM19C550 min.410 min.15 min.10 min.
Grade 20ASTKM20A540 min.390 min.23 min.18 min.7/8 D90°6 D

Steel Grades in JIS G3445

We offer JIS G3445 tubes in various steel grades, including STKM11A, STKM12(A,B,C), STKM13(A,B,C), STKM14(A,B,C), and up to STKM20(A, B, C). Each grade has its unique properties, ensuring that our clients can choose the one that best fits their requirements.

Reference Resource

Our Advantages

  1. Over 25 years of experience in pipeline production and installation.
  2. Comprehensive inspection equipment.
  3. Independent product serial numbers for traceability.
  4. Advanced production equipment – Seamer high-frequency welding machine from the United States.
  5. Complete qualifications – API 5L/API 5CT/FM/UL fire pipe certification, etc.
  6. Wide range of products – independently developed solar torque tubes, highly favored in the European market.
  7. Customers spread across the globe.
  8. Excellent after-sales service and sense of responsibility.

Application Scenarios

Our steel pipes are engineered to withstand high temperatures, corrosive environments, and varying pressures, ensuring reliability and safety in the complex petrochemical processes. 

Whether it’s transferring crude oil, natural gas, or chemical intermediates, the robustness and versatility of steel pipes make them indispensable components of the plant’s infrastructure, contributing to efficient production and maintenance of stringent safety standards.

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