STKM 11A Carbon Steel Seamless Tubes
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JIS G 3445 Grade STKM11A Steel Tube, stkm11a Chemical Composition, stkm11a equivalent material, stkm11a material properties, stkm11a yield strength, STKM 11A Steel Tube Supplier.
Solitaire Steel is a well-established manufacturer and supplier of STKM11A cold-rolled tubes across the country. The JIS G3445 STKM11A standard is widely used for carbon seamless steel tubing in mechanical parts. These low-carbon steel pipes contain a maximum of 0.12% carbon and 0.60% manganese, making them easy to shape and form. Known as CS (Carbon Steel) or MS (Mild Steel) pipes, they offer superior mechanical properties compared to high-carbon steel pipes, with lower amounts of sulfur, phosphorus, and other impurities.
JIS G3445 Grade STKM11A carbon steel seamless tubes, also referred to as mild steel tubes, are affordable and versatile. With a maximum carbon content of 0.12% and manganese content of 0.60%, they are easily shaped and formed, following JIS specifications. While not as hard as high-carbon steel pipes, the surface hardness of these low-carbon steel tubes can be enhanced through carburizing.
STKM11A steel contains small amounts of silicon (Si) and manganese (Mn), along with carbon (C). The composition is tightly controlled, especially for impurities like sulfur (S) and phosphorus (P), which are typically kept below 0.035%. For high-quality grades, P and S are limited to 0.025% and 0.020%, respectively, marked with an “E” for distinction. Other elements like chromium (Cr), nickel (Ni), and copper (Cu) are also kept within strict limits—less than 0.25% Cr, 0.30% Ni, and 0.25% Cu.
JIS G3445 STKM11A steel is popular due to its high production efficiency and cost-effectiveness. It can be forged into various forms such as round, square, and flat sections, as well as plates and seamless tubes. This steel is commonly used in general structural parts, mechanical components, building structures, and fluid-carrying pipes. Depending on the application, heat treatments like normalizing or quenching may be required for added strength and durability.
Specification Of JIS G 3445 Grade STKM 11A
| Standard | JIS G3445 |
| Description Name | STKM 11A Steel tube, STKM 12A steel tubes, STKM 12C steel tubes, STKM 13A steel tubes, STKM 13C steel tubes |
| Size | 6mm-340mm |
| Wall Thickness | 1mm-50mm |
| Shape | Round |
| Production Type | Cold drawn, cold rolled or hot rolled |
| Length | Single random length/ Double random length or as customer’s actual request max length is 10m |
| Grade | STKM 11A, STKM 12A, STKM 12C, STKM 12B, STKM 13A, STKM 13B, STKM 13C, STKM 15A, STKM 17A |
STKM11A of Chemical Composition
| C | Si | Mn | P | S |
| max 0.12 | max 0.35 | max 0.6 | max 0.04 | max 0.04 |
JIS G 3445 Grade STKM11A Mechanical Properties
| Assortment | Yield point or Proof stress | Tensile strength | Elongation | Reduction of area | Charpy impact strength |
| – | N/mm 2 | N/mm 2 | % | % | J/cm 2 |
| Tubes | 290 | 35 |
STKM11A Physical Properties
| Tensile strength | 115-234 | σb/MPa |
| Yield Strength | 23 | σ 0.2 ≥/MPa |
| Elongation | 65 | δ5≥ (%) |
| ψ | – | ψ≥ (%) |
| Akv | – | Akv≥/J |
| HBS | 123-321 | – |
| HRC | 30 | – |
JIS G 3445 Grade STKM11A Tolerance on Outside Diameter
| Division | Tolerances on outside diameter |
| No. 1 | Under 50mm ±0.5mm |
| 50mm or over ±1% | |
| No. 2 | Under 50mm ±0.25mm |
| 50mm or over ±0.5% | |
| No. 3 | Under 25mm ±0.12mm |
| 25mm or over to and excl. 40mm ±0.15mm | |
| 40mm or over to and excl. 50mm ±0.18mm | |
| 50mm or over to and excl. 60mm ±0.20mm | |
| 60mm or over to and excl. 70mm ±0.23mm | |
| 70mm or over to and excl. 80mm ±0.25mm | |
| 80mm or over to and excl. 90mm ±0.30mm | |
| 90mm or over to and excl.100mm ±0.40mm | |
| 100mm or over ±0.50% |
Tolerance of Thickness
| Division | Tolerances on wall thickness |
| No. 1 | Under 4mm |
| +0.6mm | |
| -0.5mm | |
| 4mm or over | |
| 15% | |
| -12.50% | |
| No. 2 | Under 3mm |
| ±0.3mm | |
| 3mm or over |
Heat Treatment Regime STKM11A
| Annealing | Quenching | Tempering | Normalizing | Q & T |
| √ | √ | √ | √ | √ |
STKM11A Range of Products
| Product type | Product | Dimension | Processes | Deliver Status |
| Plates / Sheets | Plates / Sheets | 0.08-200mm(T)*W*L | Forging, hot rolling and cold rolling | Annealed, Solution and Aging, Q+T, ACIDWASHED, Shot Blasting |
| Steel Bar | Round Bar, Flat Bar, Square Bar | Φ8-1200mm*L | Forging, hot rolling and cold rolling, Cast | Black, Rough Turning, Shot Blasting, |
| Coil / Strip | Steel Coil /Steel Strip | 0.03-16.0x1200mm | Cold-Rolled & H | Annealed, Solution and Aging, Q+T, ACIDWASHED, Shot Blasting |
| Pipes / Tubes | Seamless Pipes/Tubes, Welded Pipes/Tubes | OD:6-219mm x WT:0.5-20.0mm | Hot extrusion, Cold Drawn, Welded | Annealed, Solution and Aging, Q+T, ACIDWASHED |
STKM11A Industrial Applications
STKM11A steel tubes are used in various industries due to their strength and versatility:
- Machinery: These tubes are essential for manufacturing machine parts, including vehicle components like steering shafts, shock absorbers, and drive shafts.
- Construction: They play a key role in building steel structures such as bridges, towers, and buildings.
- Fluid Transfer: STKM11A tubes are used in hydraulic lines and other fluid transfer systems.
- Sporting Equipment: These tubes are popular for making durable bicycle frames and other sports gear.
- Furniture: STKM11A tubes are also used to create sturdy and long-lasting furniture.
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FAQs
STKM 11A is a low-carbon steel with good formability, weldability, and low cost, making it ideal for general-purpose applications in automotive and structural industries.
STKM11A, per Japanese Industrial Standards (JIS), is a classification for carbon steel tubes designed for general structural applications, known for good formability and cost-effectiveness.
JIS G3445 STKM11A is a carbon seamless steel tubing standard for mechanical parts. With low carbon and manganese content, it’s easily shaped and formed, often called CS or MS pipes.
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