ASTM A299 Grade A Steel Plate | A299 Gr.A Mn-Si Vessel Plate
What is ASTM A299 Grade A Steel?
ASTM A299 Grade A is the workhorse grade in ASTM A299/A299M. The specification covers carbon-manganese-silicon steel plates for welded boilers and other pressure vessels. Two grades are listed: Grade A and Grade B. Grade A is the plate most buyers type into a search box. Grade B is the higher-strength sister. As Direct Mill Supply by SHH STEEL, the plate is produced to ASTM A299/A299M.
The same plate is written A299 Gr.A, A299GRA, A299 GR A, A299 Grade A, ASTM A299 Gr.A, ASME SA299 Grade A, SA299 Gr.A, SA299GRA and A/SA299 Grade A. They all mean Grade A. ASME SA-299/SA-299M is the Code companion used when the vessel will be stamped to ASME Section VIII.
This is not fine-grain carbon like SA516 Gr.70 or A516 Gr.70. Those pages are the everyday Code carbon family with a 485–620 MPa tensile table and a toughness habit shops know by heart. A299 Grade A is silicon-killed carbon with a higher manganese band and a 515–655 MPa tensile table. The two plates can sit on the same bid list. They are not interchangeable on a stamped vessel without a drawing change.
This is not SA515 Gr.70 or A515 Gr.70. SA515 / A515 is intermediate-and-higher-temperature silicon-killed carbon. A299 is manganese-silicon carbon aimed at boilers and vessels that want more Mn-Si strengthening. This is not SA285 Gr.C or A285 Gr.C. A285 Grade C stops at 380–515 MPa and at 50 mm.
It is not Mn-Mo plate like SA302 Gr.B or A302 Gr.B. It is not nickel plate like SA203 Gr.A or A203 Gr.A. It is not Cr-Mo like SA387 Gr.22 Cl.2. It is not QT 690 like SA517 Gr.Q. A mill cannot recertify those heats as A299GRA.
The steel follows ASTM A20 / ASME SA-20. Plates 50 mm and under are commonly supplied as-rolled and may be ordered normalized or stress-relieved, or both. Plates over 50 mm are normally normalized. Maximum thickness is limited only by the ability of the composition to meet the mechanical table. Mills commonly offer about 8–150 mm.
For Code work the plate is dual-marked ASTM A299 Grade A / ASME SA299 Grade A. Certificates can be EN 10204 3.1 or EN 10204 3.2.
When a project is still choosing carbon vessel plate, a China mill Agent path through SHH STEEL puts A299GRA next to SA516 Gr.60, SA537 Cl.1 and SA285 Gr.A, so the buyer can see whether they need Mn-Si A299, fine-grain A516, heat-treated A537 or low-tensile A285.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | ASTM A299 Grade A / A299 Gr.A / A299GRA | Confirmed |
| Product Specification | ASTM A299/A299M | Applied |
| Companion Spec | ASME SA299 Grade A / SA299GRA | Dual cert available |
| General Requirements | ASTM A20 / ASME SA-20 | Applied |
| Code Context | ASME Section VIII when dual marked | As specified |
| Product Form | Carbon-manganese-silicon vessel plate | Available |
| Usual Delivery | As-rolled ≤50 mm; normalized >50 mm | Confirmed |
| Typical Supply | 8 mm – 150 mm | By mill enquiry |
| Width / Length | Up to about 4000 mm / 12000 mm | Mill capability |
| Certification | EN 10204 3.1 or 3.2 / third-party | As ordered |
This plate is a vessel product. It is not structural ASTM A36 steel plate.
Chemical Composition
Chemistry for ASTM A299 Grade A is reported as heat analysis and product analysis under ASTM A299/A299M Table 1. Carbon and manganese both change at 25 mm.
Heat Analysis — ASTM A299 Grade A / A299 Gr.A
| Element | ≤ 25 mm | Over 25 mm |
|---|---|---|
| Carbon (C), max | 0.26 | 0.28 |
| Manganese (Mn) | 0.90 – 1.40 | 0.90 – 1.50 |
| Phosphorus (P), max | 0.025 | 0.025 |
| Sulfur (S), max | 0.025 | 0.025 |
| Silicon (Si) | 0.15 – 0.40 | 0.15 – 0.40 |
Product Analysis — A299GRA / SA299 Grade A
| Element | ≤ 25 mm | Over 25 mm |
|---|---|---|
| Carbon (C), max | 0.26 | 0.28 |
| Manganese (Mn) | 0.84 – 1.52 | 0.84 – 1.62 |
| Phosphorus (P), max | 0.025 | 0.025 |
| Sulfur (S), max | 0.025 | 0.025 |
| Silicon (Si) | 0.13 – 0.45 | 0.13 – 0.45 |
Carbon maxima apply to both heat and product analysis. Grade B allows more carbon: 0.28% to 25 mm and 0.30% over 25 mm. A Grade B heat cannot be stamped Grade A if carbon sits above the Grade A cap.
Manganese is the strengthening lever. Heat Mn is 0.90–1.40% to 25 mm and 0.90–1.50% over 25 mm. Silicon is killed-steel silicon, 0.15–0.40% heat. That combination is why this page is titled Mn-Si vessel plate instead of sharing a generic carbon name with A516 Gr.60.
If the drawing says ASTM A299 Grade A or A299GRA, the ladle must sit in the Grade A table. SHH STEEL reports heat analysis on every certificate and adds product analysis when A20 / SA-20 or the vessel specification requires it.
Tighter P, S or residuals are supplementary. Vacuum treatment is available when written on the order.
Mechanical Properties
Yield of Grade A drops 15 MPa once thickness passes 25 mm. Tensile stays in one window.
Tensile Requirements — ASTM A299 Grade A per ASTM A299/A299M
| Property | ≤ 25 mm (1 in.) | Over 25 mm (1 in.) |
|---|---|---|
| Tensile strength | 515 – 655 MPa (75 – 95 ksi) | 515 – 655 MPa (75 – 95 ksi) |
| Yield strength, min | 290 MPa (42 ksi) | 275 MPa (40 ksi) |
| Elongation in 200 mm (8 in.), min | 16% | 16% |
| Elongation in 50 mm (2 in.), min | 19% | 19% |
Yield is determined by the 0.2% offset method or the 0.5% extension-under-load method. A 20 mm plate is tested to 290 MPa. A 30 mm plate is tested to 275 MPa. Do not apply the thin-line yield to a 40 mm plate and call the heat compliant.
Grade B in the same specification is 550–690 MPa tensile, with 325 MPa yield to 25 mm and 310 MPa over 25 mm. If the drawing says Grade A, do not ship Grade B as a silent upgrade.
Density is 7.85 g/cm³. Hardness is not a default line. Charpy is not a hidden default. If the vessel needs 27 J at 0 °C or −20 °C, write it as a supplementary requirement. Do not assume the SA516 impact habit.
Compare nearby carbon pages. SA516 Gr.70 is 485–620 MPa. SA515 Gr.70 is also 485–620 MPa but aimed at higher-temperature silicon-killed service. SA285 Gr.C is only 380–515 MPa. A299 Grade A sits above those carbon windows on manganese.
Material Comparison
| Grade | Route | Strength idea | Swap? |
|---|---|---|---|
| ASTM A299 Gr.A / ASME SA299 Gr.A | C-Mn-Si | 515–655 MPa / 290–275 MPa yield | This page |
| ASTM A299 Gr.B / ASME SA299 Gr.B | C-Mn-Si | 550–690 MPa / 325–310 MPa yield | Same family, higher strength |
| SA516 Gr.70 | Fine-grain carbon | 485–620 MPa | No |
| A515 Gr.70 | Si-killed high-temp carbon | 485–620 MPa | No |
| A285 Gr.C | Low/intermediate carbon PV | 380–515 MPa | No |
| SA302 Gr.B | Mn-Mo | Intermediate alloy | No |
| SA537 Cl.1 | Heat-treated carbon | Different HT route | No |
| SA203 Gr.D | 3.5Ni low-temp | Nickel family | No |
Order ASTM A299 Grade A when the drawing names Grade A. SHH STEEL does not swap A299GRA for A516 Gr.70 without a written revision.
Boiler and Pressure Vessel Service
ASTM A299 Grade A is selected for welded boilers and vessels that want C-Mn-Si strength without moving into Mn-Mo or Cr-Mo. When the vessel is ASME stamped, allowable stress comes from Section II Part D for SA-299 Grade A after dual marking. Impact temperature is an order number.
Typical use is boiler drums, steam drums and process vessels specified to A299 / SA299. It is not a creep Cr-Mo grade and not a cryogenic nickel grade.
Weldability
A299GRA is silicon-killed carbon with a high manganese band. Welding is Code welding, not structural fillet practice.
Procedures for Code work are qualified to ASME Section IX. Low-hydrogen consumables such as E7018 (AWS A5.1) are the usual shop choice. Carbon equivalent should be calculated from the actual ladle. Preheat depends on thickness, restraint and hydrogen.
PWHT follows the vessel specification. Simulated PWHT of mill coupons should be on the purchase order when the shop cycle is known.
Do not copy a SA387 Gr.22 Cl.2 or SA517 Gr.Q procedure onto ASTM A299 Grade A. The fabricator owns the WPS.
Heat Treatment
Plates 50 mm and under are normally supplied as-rolled. They may be ordered normalized, stress-relieved, or both.
Plates over 50 mm are normally normalized.
As-rolled thick plate is not the default for A299 Grade A above 50 mm. SHH STEEL reports the actual delivery condition on the MTC.
Delivery Condition
Usual delivery is as-rolled to 50 mm and normalized above 50 mm, unless the order says otherwise.
The certificate lists ASTM A299 Grade A and, when dual certified, ASME SA299 Grade A; heat number; heat analysis; product analysis when ordered; tensile results by the 25 mm yield line; heat-treatment condition; and supplementary tests.
Certificates may be EN 10204 3.1 or EN 10204 3.2.
Dimensions
Usual supply range from SHH STEEL for A299 Gr.A Mn-Si vessel plate:
- Thickness: 8 mm – 150 mm
- Width: up to about 4000 mm
- Length: up to about 12000 mm
State thickness clearly. At 25 mm the yield line changes. At 50 mm the usual heat-treatment practice changes.
Tolerances
Dimensional limits follow ASTM A20 / ASME SA-20. UT to A435 or A578 is added when specified.
Supplementary Requirements
Most export ASTM A299 Grade A orders add extras. SHH STEEL does not assume them.
Simulated PWHT. Same-heat coupons follow the vessel cycle.
Charpy details. Temperature, energy and location as agreed.
NDE. UT to A435 / A577 / A578.
Restricted chemistry. Tighter P, S or residuals.
HIC / NACE. Only when cited.
Z-direction. A770 or Z15/Z25/Z35 when written.
Third-party. EN 10204 3.2.
Equivalent Material Grades
| Designation | Standard | Notes |
|---|---|---|
| ASTM A299 Grade A / A299 Gr.A / A299GRA | ASTM A299/A299M | Product name on this page |
| ASME SA299 Grade A / SA299 Gr.A / SA299GRA | ASME SA-299/SA-299M | Code companion |
| ASTM A299 Grade B | A299/A299M | Higher strength in the same spec |
| EN 10028-2 P355GH related | EN | Project comparison only |
| JIS G3118 SGV450 / SGV410 related | JIS | Japanese PV comparison |
| GB/T 713 Q370R related | GB | Confirm chemistry and tensile |
| A537CL1 | ASTM A537 | Heat-treated carbon; not a substitute |
| A203 Gr.A | ASTM A203 | Nickel family; not a substitute |
For stamping, write ASTM A299 Grade A or dual A299 / SA299 Grade A.
Applications
| Industry | Typical components |
|---|---|
| Boilers | ASTM A299 Grade A drums and A299GRA shells |
| Petrochemical | A299 Grade A process vessels |
| Energy | ASTM A299 Grade A Mn-Si vessel plate |
| Dual-certified export | A299 / SA299 Gr.A plate |
| Fabrication | A299GRA cut to nest sizes |
Do not use this grade as a silent stand-in for SA203 Gr.D or SA517 Gr.S.
Why Choose SHH STEEL
SHH STEEL works as a China Mill Direct Exporter for plates to ASTM A299/A299M. On ASTM A299 Grade A that means mill pricing, dual A299/SA299 marking, thickness-correct carbon and manganese bands at 25 mm, as-rolled or normalized delivery recorded on the MTC, 3.1 as standard and 3.2 when specified.
We keep the order on the right specification. Grade A is not Grade B. A299 is not SA516 Gr.55. A299 is not SA285 Gr.B. If the drawing wants fine-grain impact-tested carbon, we point the inquiry to SA516 / A516. If it wants nickel low-temp, we point it to SA203 / A203.
Company scope: China steel Mill Agent-SHH STEEL.
FAQ
- What names are used for ASTM A299 Grade A?
- Buyers write A299 Gr.A, A299GRA, A299 GR A, A299 Grade A, ASME SA299 Grade A, SA299 Gr.A and SA299GRA. SHH STEEL prints the wording on the purchase order.
- Is ASTM A299 Grade A the same as ASME SA299 Grade A?
- Chemistry and tensile limits match. ASTM A299 is the product spec. ASME SA-299 is the Code version. As China mill-Direct Supply, SHH STEEL dual-certifies A299 Gr.A / SA299 Gr.A when the vessel must be stamped.
- What is the yield strength of A299 Gr.A?
- 290 MPa through 25 mm. 275 MPa over 25 mm. Tensile is 515–655 MPa at all thicknesses, per ASTM A299.
- Why specify Grade A instead of Grade B?
- Grade B is 550–690 MPa tensile with higher carbon and higher yield. Follow the grade on the drawing.
- Is A299GRA the same as A516 Gr.70 or A515 Gr.70?
- No. Those are different carbon vessel specifications. ASTM A299 Grade A is C-Mn-Si plate under A299/A299M.
- Is heat treatment mandatory for A299 Gr.A?
- Plates over 50 mm are normally normalized. Plates 50 mm and under are usually as-rolled unless ordered normalized or stress-relieved.
- Can welding of A299 Gr.A be qualified to ASME Section IX?
- Yes, after dual marking or when the construction code requires it. Use a low-hydrogen WPS written for this Mn-Si carbon. The fabricator owns the procedure.
- Can SHH STEEL issue EN 10204 3.2 on ASTM A299 Grade A?
- Yes. EN 10204 3.1 is standard. EN 10204 3.2 is arranged when written on the order.
- What is the density of A299 Gr.A plate?
- 7.85 g/cm³.
Conclusion
ASTM A299 Grade A Steel Plate is the manganese-silicon carbon vessel grade in ASTM A299/A299M. Whether the inquiry says A299 Gr.A, A299GRA, A299 Grade A, SA299 Gr.A or ASME SA299 Grade A, SHH STEEL supplies plate with heat and product analysis, thickness-correct yield at 25 mm, as-rolled or normalized delivery, and EN 10204 3.1 or 3.2 certification.
As a China mill Distributor, SHH STEEL provides ASTM A299 Grade A / A299 Gr.A Mn-Si Vessel Plate for boilers and dual-certified Section VIII work.
Contact SHH STEEL for mill rolling, dual A299/SA299 marking, 3.2 inspection or a quotation.
ASTM A299 Grade A Steel Plate, A299 Gr.A, A299GRA, ASME SA299 Grade A, Mn-Si vessel plate, A299 Grade A supplier, Direct Mill Supply by SHH STEEL
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