ASME SA533 Type A Class 2 Steel Plate | SA533 Gr.A Cl.2 Mn-Mo Vessel Plate

ASME SA533 Type A Class 2 is the manganese-molybdenum, quenched-and-tempered vessel combination in ASME SA-533/SA-533M that uses Type A chemistry and the Class 2 strength table. The current specification lists five Types (A, B, C, D, E) and three Classes (1, 2, 3). Type tells the alloy. Class tells the tensile window. They are not interchangeable labels.

Type A is the only Type that is Mn-Mo without a nickel requirement. Types B, C, D and E add nickel. Class 2 is the 620–795 MPa tensile window with 485 MPa minimum yield. Class 1 on the same Type is 550–690 MPa and 345 MPa yield. Class 3 is 690–860 MPa and 570 MPa yield, with a 65 mm cap on Types A through D. As Direct Mill Supply by SHH STEEL, the plate is produced to ASME SA-533/SA-533M.

The same plate is written SA533 Type A Class 2, SA533 Gr.A Cl.2, SA533 Grade A Class 2, SA533GA CL2, SA-533 Type A Cl.2, ASTM A533 Type A Class 2, A533 Gr.A Cl.2 and A/SA533 Type A Class 2. The standard text says Type. Buyers still search Grade. They mean the same plate. Do not write this page as SA533 Gr.B Cl.2. Grade B / Type B is the nickel-bearing Type. Mixing Type A with Gr.B in one title sends the buyer to the wrong ladle.

Do not put nickel in the Type A ladle and call it Type A Class 2. If the drawing wants nickel at the Class 2 strength, the Type is B, C, D or E plus Class 2. If the drawing wants Class 1, that is a different tensile table on the same Type A chemistry, not a silent downgrade.

This is not normalized Mn-Mo plate like SA302 Gr.A or SA302 Gr.B. SA302 is the same alloy family in the normalized condition. SA533 is quenched and tempered. A 302 heat cannot be recertified as 533 Type A Class 2 without the QT cycle and the Class 2 tensile table.

This is not SA516 Gr.70 or A516 Gr.70. Those pages are fine-grain carbon. It is not SA515 Gr.70. SA515 is silicon-killed carbon for higher temperature. It is not SA285 Gr.C or A285 Gr.C. It is not SA537 Cl.1 or SA537 Cl.2. SA537 is heat-treated C-Mn-Si. It is not SA517 Gr.Q or SA517 Gr.B. SA517 is a different QT alloy family with different thickness caps. It is not nickel cryogenic plate like SA203 Gr.A or SA203 Gr.D. It is not Cr-Mo like SA387 Gr.22 Cl.2.

The steel shall be killed and shall meet fine austenitic grain practice under ASME SA-20. Plates are quenched and then tempered at not less than 595 °C (1100 °F), with a minimum hold of 0.5 h/in. (1.2 min/mm) and not less than 0.5 h. As-rolled SA533 is crack-sensitive in transit, especially above about 25 mm, and may ship as-rolled only by written agreement.

Current practice normally limits Type A Class 2 to about 300 mm. Class 3 on Types A–D is capped at 65 mm. Minimum nominal thickness is 6.5 mm. For Class 2 and Class 3, the specification allows a higher manganese maximum when Supplementary Requirement S3 is invoked. That option is not automatic. It must be written on the order.

For Code work the plate is used under ASME Section VIII. Dual marking ASME SA533 Type A Class 2 / ASTM A533 Type A Class 2 is available. Certificates can be EN 10204 3.1 or EN 10204 3.2.

When a project is still choosing QT vessel plate, a China mill Agent path through SHH STEEL puts SA533 Type A Cl.2 next to SA302 Gr.A, SA537 Cl.2 and A36 steel plate, so the buyer can see whether they need QT Mn-Mo at Class 2, normalized Mn-Mo, heat-treated carbon or structural carbon. Company scope: China steel Mill Agent-SHH STEEL.

This plate is a vessel product. It is not structural ASTM A36 steel plate. It is not low-tensile carbon like SA285 Gr.A. It is not fine-grain carbon like SA516 Gr.60.

Chemistry for ASME SA533 Type A is the Type table. Class 1, Class 2 and Class 3 share Type A chemistry unless Supplementary Requirement S3 is used to raise manganese on Class 2 or Class 3.

Heat Analysis — ASME SA533 Type A

Product Analysis — SA533 Gr.A / A533 Type A

Type B requires nickel about 0.40–0.70% heat. Type C is higher nickel. Type D is lower nickel. Type E has a tighter residual and carbon practice. Type A has no nickel line. If a ladle carries intentional nickel in the Type B band, it is not Type A, and it is not this page.

For Class 2 and Class 3, the specification allows the maximum manganese to be increased to 1.60% heat and 1.65% product when S3 is specified. SHH STEEL applies that increase only when the purchase order says S3. Class 2 strength is made first by quench and temper, not by assuming extra manganese.

Compare that ladle with SA302 Gr.A (normalized Mn-Mo), SA302 Gr.C (Mn-Mo-Ni), SA387 Gr.11 Cl.2 (Cr-Mo) and SA516 Gr.70 (carbon). None of those tables is SA533 Type A.

If the drawing says ASME SA533 Type A Class 2 or SA533 Gr.A Cl.2, the ladle must sit in the Type A table and the tensile test must sit in the Class 2 window. SHH STEEL reports heat analysis on every certificate and adds product analysis when SA-20 requires it.

Class 2 is the strength line. Type A only tells the alloy.

Tensile Requirements — ASME SA533 Class 2

Class 1 on the same Type is 550–690 MPa tensile and 345 MPa yield, with 18% elongation. Class 3 is 690–860 MPa tensile and 570 MPa yield, with 16% elongation and a 65 mm cap on Types A–D. A Class 1 heat cannot be stamped Class 2 because someone wants the higher name. A Class 2 heat cannot be stamped Class 1 as a silent substitute without a drawing change.

Density is 7.85 g/cm³. Hardness is not a default line in SA-533. Charpy is not a hidden default. Thick-wall Class 2 work almost always writes impact temperature, location and orientation as extras.

Compare SA537 Cl.2 and SA517 Gr.Q. Overlap on a yield number is not a substitute. SA537 Class 2 is carbon-manganese-silicon QT. SA517 Grade Q is a different QT alloy with a different thickness rule.

Order ASME SA533 Type A Class 2 when the drawing names Type A and Class 2. SHH STEEL does not swap this plate for A516 Gr.70 or A517 Gr.Q.

ASME SA533 Type A Class 2 is selected for welded vessels that need QT Mn-Mo strength above Class 1 and do not want a nickel addition. Allowable stress comes from ASME Section II Part D for SA-533 Type A Class 2 after the plate is Code-marked.

Typical use is heavy-wall process vessels, high-pressure drums and shells specified to SA-533 Type A Class 2. Nuclear beltline work more often names Type B. If the drawing says Type B Class 2, this page is the wrong purchase.

It is not a replacement for SA387 Gr.91 Cl.2 creep service or SA203 Gr.E nickel low-temp service. Those drawings name different alloys and different design temperatures.

SA533 Gr.A Cl.2 is QT Mn-Mo at a higher strength than Class 1. Welding is Code welding, not structural fillet practice from ASTM A36 steel plate.

Procedures are qualified to ASME Section IX. Low-hydrogen practice is mandatory. Consumables must match the required joint strength and toughness after any PWHT. Carbon can sit at 0.25%. Molybdenum is in the 0.45–0.60% heat band. Calculate carbon equivalent from the actual ladle.

Preheat depends on thickness, restraint, hydrogen and the qualified WPS. Thick Class 2 plate is not a 12 mm carbon fillet. After welding, many shops want to PWHT. Simulated PWHT of mill coupons should be on the purchase order when the vessel cycle is known.

Do not copy a SA387 Gr.22 Cl.1 Cr-Mo procedure or a SA517 Gr.A QT procedure onto Type A Class 2 without review. The fabricator owns the WPS.

Plates shall be quenched and tempered.

Tempering shall be at a suitable temperature to produce the specified Class 2 properties, but not less than 595 °C (1100 °F), with a minimum holding time of ½ h/in. (1.2 min/mm) and not less than ½ h.

As-rolled delivery is not the specified condition. As-rolled shipping is crack-sensitive above about 25 mm and requires written agreement between mill and buyer. SHH STEEL reports quench medium or practice as applicable, temper temperature and hold on the MTC for every SA533 Type A Class 2 plate.

Do not apply the normalize-only route used for SA302 Gr.A and call the plate SA533 Class 2.

Usual delivery is quenched and tempered Type A Class 2 plate.

The certificate lists ASME SA533 Type A Class 2 and, when dual certified, ASTM A533 Type A Class 2; heat number; heat analysis; product analysis when ordered; tensile results to the Class 2 table; QT temperatures; Charpy results when ordered; and supplementary tests.

Surface is vessel-plate quality. Shot blasting and shop primer are available.

Certificates may be EN 10204 3.1 or EN 10204 3.2. BV, LR, DNV, TUV, SGS or the buyer’s agency can witness rolling, quenching, tempering and testing when the order says so.

Usual supply range from SHH STEEL for SA533 Gr.A Cl.2 Mn-Mo vessel plate:

• Thickness: 6.5 mm – about 300 mm for Class 2 (current practice on Type A)
• Width: up to about 4000 mm
• Length: up to about 12000 mm

Class 3 is not this page. Class 3 on Type A stops at 65 mm. If the inquiry is Class 3, the thickness plan and the tensile table both change.

Dimensional limits follow ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances.

Ultrasonic testing to A435, A577 or A578 is commonly added on thick QT plate. Extra-flatness is a negotiated item.

Most export ASME SA533 Type A Class 2 orders add extras. SHH STEEL does not assume them.

S3 manganese increase. Allowed for Class 2 and Class 3. Written on the order or not applied.

Charpy details. Temperature, energy, location and orientation. Thick-wall Class 2 work almost always writes this.

Simulated PWHT. Same-heat coupons follow the vessel cycle. Tensile and Charpy are then run on those coupons.

NDE. UT to A435 / A577 / A578; edge MT/PT after cutting.

Restricted residuals. When high-restraint or nuclear-adjacent work specifies them.

Restricted P, S. Tighter than 0.025% when specified.

Third-party. Witness of QT and testing. Output can be EN 10204 3.2.

If an item is not on the purchase order, it is not assumed, not tested and not printed as if it were.

For stamping, write ASME SA533 Type A Class 2 or dual SA533 / A533 Type A Class 2.

Do not use this grade as a silent stand-in for SA203 Gr.B or SA517 Gr.S. Those drawings name different alloys and different heat treatments.

SHH STEEL works as a China Mill Direct Exporter for plates to ASME SA-533/SA-533M. On ASME SA533 Type A Class 2 that means mill pricing, dual SA533/A533 marking, Type A chemistry without a nickel requirement, recorded quench and temper, Class 2 tensile results at 620–795 MPa and 485 MPa yield, 3.1 as standard and 3.2 when specified.

We keep the order on the right Type and Class. Type A is not Type B. Class 2 is not Class 1 and is not Class 3. SA533 is not SA516 Gr.55. SA533 is not SA285 Gr.A. SA533 Type A Cl.2 is not SA517 Gr.Q. If the drawing names nickel, we point the inquiry to Type B. If it names normalized Mn-Mo, we point it to SA302. If it names Class 1, we will not ship Class 2 and call it close.

Company scope: China steel Mill Agent-SHH STEEL.

ASME SA533 Type A Class 2 Steel Plate is quenched-and-tempered manganese-molybdenum vessel plate under ASME SA-533/SA-533M. Whether the inquiry says SA533 Type A Class 2, SA533 Gr.A Cl.2, SA533 Grade A Class 2 or A533 Type A Class 2, SHH STEEL supplies plate with Type A chemistry (no nickel requirement), recorded QT, Class 2 tensile results at 620–795 MPa, and EN 10204 3.1 or 3.2 certification.

As a China mill Distributor, SHH STEEL provides ASME SA533 Type A Class 2 / SA533 Gr.A Cl.2 Mn-Mo Vessel Plate for ASME Section VIII work.

Contact SHH STEEL for mill rolling, dual SA533/A533 marking, 3.2 inspection or a quotation.

ASME SA533 Type A Class 2 Steel Plate, SA533 Gr.A Cl.2, SA533 Grade A Class 2, ASTM A533 Type A Class 2, Mn-Mo QT vessel plate, Direct Mill Supply by SHH STEEL