Premium SA213 T12 Seamless Alloy Tube for Superheaters, Reheaters, Economizers, Boiler Water Walls, Heat Exchangers, and Moderate High-Temperature Piping
Womic Steel produces high-quality SA213 T12 Seamless Alloy Steel Tube, manufacturing chromium-molybdenum (1Cr-0.5Mo) ferritic alloy tubes in accordance with ASTM A213 / ASME SA213 specifications. Our SA213 T12 tubes meet the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, with a minimum tensile strength of 415 MPa and good creep resistance at elevated temperatures up to 540°C (1000°F). These seamless alloy tubes are the ideal choice for superheaters, reheaters, economizers, boiler water walls, heat exchangers, and moderate high-temperature industrial piping, offering a balance between cost, weldability, and creep strength. T12 is widely used in power generation, industrial boilers, and refinery applications where moderate elevated temperature service is required.
Manufacturer: Womic Steel
1. Product Definition and Scope
SA213 T12 (UNS K11562) is a seamless ferritic alloy steel tube specified under ASTM A213 / ASME SA213 for use in boilers, superheaters, heat exchangers, and other pressure-containing equipment operating at moderate elevated temperatures. The “T12″ designation indicates a nominal composition of 1% chromium and 0.5% molybdenum. T12 provides improved creep strength over carbon steel at moderate cost, with good weldability and fabricability. It is often used as an economical alternative to T11 in less severe service conditions.
Manufacturing Process: T12 tubes are manufactured by the seamless process (hot-finished or cold-finished) and are typically supplied in the annealed or normalized and tempered condition.
Grade Designation:
| Designation | Meaning |
| SA213 | ASME specification for seamless ferritic and austenitic alloy-steel tubes for boilers, superheaters, and heat exchangers |
| T12 | Grade designation: 1% Chromium – 0.5% Molybdenum ferritic alloy |
| UNS K11562 | Unified numbering system designation for T12 |
Equivalent Standards and Grades:
| Standard | Equivalent Grade |
| ASTM A213 / ASME SA213 | T12 |
| ASTM A335 | P12 (pipe form) |
| EN 10216-2 | 13CrMo4-5 (1.7335) |
| DIN 17175 | 13CrMo44 |
| JIS G3462 | STBA 22 |
| BS 3059 | 621-490 |
Manufacturer: Womic Steel
2. Chemical Composition Requirements
The chemical composition of SA213 T12 is similar to T11 but with slightly lower chromium (1.0% vs 1.25%). Both grades are often interchangeable in service.
SA213 T12 Chemical Composition (Heat Analysis – Seamless Tube):
| Element | Composition (%) – Minimum | Composition (%) – Maximum |
| Carbon (C) | 0.05 | 0.15 |
| Manganese (Mn) | 0.30 | 0.61 |
| Phosphorus (P) | — | 0.025 |
| Sulfur (S) | — | 0.025 |
| Silicon (Si) | 0.10 | 0.50 |
| Chromium (Cr) | 0.80 | 1.25 |
| Molybdenum (Mo) | 0.44 | 0.65 |
Product Analysis Permitted Variations:
| Element | Permitted Variation (max) |
| Carbon (C) | +0.02 |
| Manganese (Mn) | +0.05 |
| Phosphorus (P) | +0.005 |
| Sulfur (S) | +0.005 |
| Silicon (Si) | +0.05 |
| Chromium (Cr) | +0.10 |
| Molybdenum (Mo) | +0.05 |
Composition Notes:
| Element | Engineering Note |
| Chromium (0.80-1.25%) | Provides mild oxidation resistance; lower than T11 |
| Molybdenum (0.44-0.65%) | Primary contributor to creep strength at elevated temperatures |
| Carbon (0.05-0.15%) | Low carbon range for improved weldability |
| Silicon (0.10-0.50%) | Deoxidation; contributes to oxidation resistance |
T12 is essentially a lower-chromium version of T11. In many specifications, T11 and T12 are considered interchangeable for pressure part construction.
3. Mechanical Properties
Tensile Requirements (Room Temperature):
| Property | Minimum | Typical | Unit |
| Tensile Strength | 415 MPa (60 ksi) | 450-550 MPa | — |
| Yield Strength (0.2% offset) | 205 MPa (30 ksi) | 280-350 MPa | — |
| Elongation in 2 in. or 50 mm | 30% | 35-40% | — |
Elongation Adjustment for Thin Walls:
| Wall Thickness | Minimum Elongation |
| 5/16 in. (8.0 mm) and over | 30% |
| 1/4 in. (6.4 mm) | 27% |
| 3/16 in. (4.8 mm) | 24% |
| 1/8 in. (3.2 mm) | 21% |
| 1/16 in. (1.6 mm) | 18% |
| 0.035 – 0.022 in. (0.9 – 0.6 mm) | 17% |
| 0.022 – 0.015 in. (0.6 – 0.4 mm) | 16% |
When the wall thickness is between the values above, the minimum elongation shall be determined by the formula: E = 48t + 15.00 (in.) or E = 1.87t + 15.00 (mm).
Hardness Requirements:
| Property | Maximum |
| Brinell Hardness (HBW) | 163 |
| Rockwell Hardness (HRB) | 85 |
High-Temperature Tensile Properties (Reference Values):
| Temperature (°C) | Tensile Strength (MPa) | Yield Strength (MPa) |
| 20 | 450-550 | 280-350 |
| 300 | 420-500 | 240-300 |
| 400 | 400-480 | 220-280 |
| 450 | 380-460 | 200-260 |
| 500 | 350-430 | 180-240 |
| 540 | 300-380 | 150-200 |
Creep Rupture Strength (Typical Values):
| Temperature (°C) | 10,000 Hour Stress (MPa) | 100,000 Hour Stress (MPa) |
| 450 | 120-140 | 80-95 |
| 480 | 90-110 | 60-75 |
| 510 | 70-85 | 45-55 |
| 540 | 50-65 | 30-40 |
T12′s creep strength is similar to T2 and T11 at temperatures up to 540°C, making it suitable for superheater and reheater sections where metal temperatures do not exceed 540°C.
4. Heat Treatment Requirements
T12 tubes shall be reheated for heat treatment according to the following methods.
Heat Treatment Requirements:
| Grade | Heat Treat Type | Subcritical Annealing or Tempering Temperature (min) |
| T12 (K11562) | Full or isothermal anneal; normalize and temper | 1200°F (650°C) min |
Heat Treatment Process Details:
| Condition | Process | Temperature Range | Application |
| Normalized | Heating followed by air cooling | 900-930°C (1650-1700°F) | Refine grain structure |
| Tempered | Reheating after normalizing | 650-730°C (1200-1350°F) | Develop final mechanical properties |
| Full Annealed | Slow cooling from austenitizing temperature | 870-900°C (1600-1650°F) | Softest condition for forming |
Manufacturer: Womic Steel performs heat treatment in accordance with ASTM A213 / ASME SA213 requirements. Heat treatment certificates are provided upon request.
5. Dimensional Tolerances
Outside Diameter Tolerances – Hot Finished:
| OD Range (mm) | Tolerance (mm) |
| OD ≤ 101.6 | +0.4 / -0.8 |
| 101.6 < OD ≤ 190.5 | +0.4 / -1.2 |
| 190.5 < OD ≤ 228.6 | +0.4 / -1.6 |
Outside Diameter Tolerances – Cold Drawn:
| OD Range (mm) | Tolerance (mm) |
| OD < 25.4 | ±0.10 |
| 25.4 ≤ OD ≤ 38.1 | ±0.15 |
| 38.1 < OD < 50.8 | ±0.20 |
| 50.8 ≤ OD < 63.5 | ±0.25 |
| 63.5 ≤ OD < 76.2 | ±0.30 |
| 76.2 ≤ OD ≤ 101.6 | ±0.38 |
| 101.6 < OD ≤ 190.5 | +0.38 / -0.64 |
| 190.5 < OD ≤ 228.6 | +0.38 / -1.14 |
Wall Thickness Tolerances – Hot Finished:
| OD Range | WT Range | Tolerance (%) |
| OD ≤ 101.6 | WT ≤ 2.4 | +40 / -0 |
| OD ≤ 101.6 | 2.4 < WT ≤ 3.8 | +35 / -0 |
| OD ≤ 101.6 | 3.8 < WT ≤ 4.6 | +33 / -0 |
| OD ≤ 101.6 | WT > 4.6 | +28 / -0 |
Wall Thickness Tolerances – Cold Drawn:
| Condition | Tolerance |
| All sizes | ±10% of nominal thickness |
Ovality Tolerances:
| Condition | Permitted Ovality |
| At tube ends | 1.0% of nominal OD |
| At other locations | 1.5% of nominal OD |
Straightness Tolerances:
| Pipe Type | Permitted Deviation |
| All Tubes | 0.2% of total length (2 mm per meter) |
Length Tolerances:
| Length Type | Tolerance |
| Random Length (RL) | 5 – 12 meters |
| Specific Length (≤ 6m) | +50 mm / -0 |
| Specific Length (6-12m) | +100 mm / -0 |
6. Available Sizes and Specifications
T12 Seamless Tube Size Range:
| Parameter | Hot Finished | Cold Finished |
| OD Range (mm) | 12.7 – 219.1 | 6.35 – 101.60 |
| OD Range (inches) | 1/2″ – 8″ | 1/4″ – 4″ |
| WT Range (mm) | 1.6 – 15.0 | 0.5 – 12.7 |
| Standard Length (m) | 6 – 12 | 6 – 12 |
Common T12 Tube Sizes (OD x WT in mm):
| OD (mm) | WT 2.5 | WT 3.0 | WT 3.5 | WT 4.0 | WT 5.0 | WT 6.0 | WT 8.0 |
| 25.4 | ✓ | ✓ | ✓ | ✓ | ✓ | — | — |
| 31.8 | — | ✓ | ✓ | ✓ | ✓ | ✓ | — |
| 38.1 | — | ✓ | ✓ | ✓ | ✓ | ✓ | — |
| 44.5 | — | — | ✓ | ✓ | ✓ | ✓ | — |
| 50.8 | — | — | — | ✓ | ✓ | ✓ | — |
| 60.3 | — | — | — | — | ✓ | ✓ | — |
| 63.5 | — | — | — | — | ✓ | ✓ | — |
| 76.2 | — | — | — | — | — | ✓ | ✓ |
| 88.9 | — | — | — | — | — | ✓ | ✓ |
| 101.6 | — | — | — | — | — | ✓ | ✓ |
U-Bend Tubes: Womic Steel can supply SA213 T12 tubes in U-bend configuration with post-bending stress relief heat treatment.
Manufacturer: Womic Steel maintains inventory of SA213 T12 seamless tubes in common sizes for immediate dispatch.
7. Inspection and Testing Requirements
| Test / Inspection | Requirement | Method | Acceptance Criteria | Frequency |
| Chemical Analysis | Required | Spectrometer | Per ASTM A213 | Per heat |
| Tensile Test | Required | ASTM A370 | ≥415 MPa / ≥205 MPa | Per heat |
| Hardness Test | Required | ASTM E10/E18 | ≤163 HBW / ≤85 HRB | Per heat |
| Flattening Test | Required | ASTM A213 | No cracks | Per lot |
| Flaring Test | Required | ASTM A213 | No cracks | Per lot |
| Hydrostatic Test or NDT | Required (100%) | ASTM A213 | No leakage or no flaws | Each tube |
Non-Destructive Testing (NDT) Options:
| Test Method | Application | Coverage | Standard |
| Eddy Current Test (ECT) | Surface and near-surface flaw detection | 100% of tube surface | ASTM E309 |
| Ultrasonic Test (UT) | Internal flaw detection | 100% of tube length | ASTM E213 |
| Hydrostatic Test | Pressure integrity verification | 100% of tubes | ASTM A1016 |
Hydrostatic Test Pressure:
● Test Pressure Formula: P = 2St/D
● Allowable Stress (S): Based on material strength at test temperature
● Hold Time: 5 seconds minimum
● Test Record: Required for each tube per ASTM A1016
Flattening Test Requirement: One flattening test shall be made on specimens from each end of one finished tube, not the one used for the flaring test, from each lot. The tube shall be flattened to a specified distance without cracking.
Flaring Test Requirement: One flaring test shall be made on specimens from each end of one finished tube, not the one used for the flattening test, from each lot.
8. Heat Treatment Verification
Required Heat Treatment Verification Records (Available upon request):
| Record Type | Information Provided |
| Heat Treatment Certificate | Time-temperature charts, furnace records |
| Normalizing Record | Temperature, hold time, cooling method |
| Tempering Record | Temperature, hold time, cooling method |
| Hardness Verification | Confirmation of ≤163 HBW after heat treatment |
9. Applications
SA213 T12 seamless tubes are used in moderate elevated temperature service.
| Industry | Application |
| Power Generation | Lower-temperature superheater sections, economizer tubes, boiler water walls, steam lines up to 450°C |
| Industrial Boilers | Package boiler tubes, waste heat recovery units |
| Heat Exchangers | Shell and tube heat exchangers for medium temperature service (400-500°C) |
| Refining | Non-critical high-temperature piping, heat exchanger bundles |
| Chemical Processing | Moderate temperature process heaters |
T12 offers a cost-effective alternative to T11 when the slightly lower chromium content is acceptable for the service conditions. It is often used in economizers and lower-temperature superheater sections of industrial boilers.
10. Comparison with T11 and T2
| Grade | Cr (%) | Mo (%) | Max Temp (°C) | Relative Cost | Application |
| T2 | 0.5 | 0.5 | 510 | Low | Moderate-temp service |
| T12 | 1.0 | 0.5 | 540 | Low-Medium | Superheater, economizer |
| T11 | 1.25 | 0.5 | 540 | Medium | Superheater sections |
T12 fills a niche between T2 and T11. While T11 is more common, T12 remains an active ASME grade and is specified in some international standards and legacy designs.
11. Welding Procedure for SA213 T12
T12 has good weldability similar to T11.
Recommended Welding Processes: SMAW, GTAW, GMAW.
Recommended Filler Metals:
| Filler Metal | AWS Classification | Application |
| ER80S-B2 | AWS A5.28 | GTAW root pass |
| E8018-B2 | AWS A5.5 | SMAW fill and cap passes |
| E7018 | AWS A5.5 | Alternative for non-critical service |
Critical Welding Requirements:
| Parameter | Requirement |
| Preheating Temperature | 100-150°C (212-302°F) for t > 12 mm; optional for thinner |
| Maximum Interpass Temperature | 250°C (482°F) |
| Post-Weld Heat Treatment (PWHT) | Required per ASME code for thickness > 19 mm (3/4 in) |
| PWHT Temperature | 620-680°C (1150-1250°F) |
| PWHT Hold Time | 1 hour per 25 mm thickness |
For most tube applications (wall thickness under 12 mm), PWHT may be waived per code, but many specifications still require it to relieve residual stress and ensure mechanical properties.
12. Traceability and Marking
Each tube shall be marked with the following information (per ASTM A1016):
| Marking Element | Example |
| Manufacturer Name | Womic Steel |
| Specification | ASTM A213 / ASME SA213 |
| Grade | T12 |
| UNS Number | K11562 |
| Size | OD x WT |
| Heat Number | H12345 |
| Length | 6.0m |
| Hydrostatic Test | Hydro / ECT |
Marking Example:
| Line | Content |
| Line 1 | Womic Steel ASTM A213/ASME SA213 T12 |
| Line 2 | 50.8mm x 4.0mm x 6.0m |
| Line 3 | Heat No: H12345 / UNS K11562 |
| Line 4 | ECT / Hydro |
13. Packaging
| Size | Method |
| Small diameter (≤ 1/2″) | Bundled with steel straps, carton boxes |
| Medium diameter (1/2″ – 2″) | Hexagonal bundles, plastic end caps |
| Large diameter (≥ 2″) | Single or bundled with fabric wrapping, plastic end caps |
14. Quality Documents
| Document | Standard | Included |
| Mill Test Report (MTR) | EN 10204 Type 3.1 | Yes |
| Heat Treatment Certificate | ASTM A213 | Yes |
| Hydrostatic Test Report | ASTM A1016 | Yes |
| NDT Report (UT/ECT) | ASTM E213/E309 | Upon request |
| Dimensional Inspection Report | ASTM A213 | Yes |
| Certificate of Origin | Chamber of Commerce | Yes |
| Third-Party Inspection | SGS, BV, DNV, TUV, LR, ABS | Optional |
15. Contact Information
Website: www.womicsteel.com
E-mail: sales@womicsteel.com
Tel / WhatsApp / WeChat:
Victor: +86 15575100681
Jack: +86 18390957568
Womic Steel – Your reliable partner for SA213 T12 seamless alloy tubes, stainless steel products, and custom solutions for boiler, superheater, heat exchanger, and industrial heat transfer applications.
Post time: Oct-10-2026