ASME SA738 Grade C Steel Plate | SA738 Gr.C Heat-Treated Vessel Plate
What is ASME SA738 Grade C Steel?
ASME SA738 Grade C, also written ASME SA738 GR.C, is heat-treated carbon-manganese-silicon steel plate under ASME SA-738/SA-738M. The specification is identical with ASTM A738/A738M. It covers five grades — Grade A, B, C, D and E — for welded pressure vessels at moderate and lower temperature service. Grade C is the 80 ksi (550 MPa) tensile class: 345 MPa yield and 550–690 MPa tensile. Grade C shall be quenched and tempered in all thicknesses. SHH STEEL is a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) for this Grade. Plate is produced to ASME SA-738/SA-738M and shipped to buyers in the USA, Europe, Middle East and Southeast Asia.
Buyers write ASME SA738 Grade C, ASME SA738 GR.C, SA738 Gr.C, SA738GRC, SA-738 Grade C, SA 738 Gr C, A738 Grade C and ASTM A738 Gr.C. A purchase order that only says “SA738” is incomplete. This page is not SA516 Gr.70. It is not Grade B. Grade B is the 85 ksi class used on many containment inquiries. It is not SA612, even though yield matches. It is not SA737 Grade C, even though the letters match.
The steel shall be killed. Fine austenitic grain practice follows ASME SA-20 / ASTM A20. Current practice normally limits Grade C thickness to about 150 mm. Dual marking SA738 / A738 Grade C is available. Certificates can be EN 10204 3.1 or 3.2. Company scope: global steel mill sourcing partner – SHH STEEL.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | ASME SA738 Grade C | Confirmed |
| Product Specification | ASME SA-738/SA-738M | Applied |
| Companion Spec | ASTM A738 Grade C | Dual cert available |
| General Requirements | ASME SA-20 / ASTM A20 | Applied |
| Steel type | Killed C-Mn-Si, QT | Confirmed |
| Strength level | 80 ksi / 550 MPa min tensile class | Confirmed |
| Heat treatment | Quenched and tempered, all thicknesses | Confirmed |
| Service idea | Moderate and lower temperature vessels | Confirmed |
| Supply role | Global steel mill sourcing partner | SHH STEEL |
| Markets | USA, Europe, Middle East, Southeast Asia | FOB / CIF as ordered |
| Certification | EN 10204 3.1 or 3.2 / third-party | As ordered |
This plate sits in pressure vessel steel plates and carbon steel plates. It does not sit with ASME SA387 Cr-Mo alloy plate or ASTM A36 steel plate structural plate.
SA-20 still governs marking, testing location, retests, repair rules and supplementary requirements unless the product specification overrides them.
Chemical Composition
ASME SA738 Grade C / ASME SA738 GR.C uses the Grade C column. Carbon heat is 0.20% max, same idea as Grade B. Manganese is a maximum that rises with thickness.
Heat Analysis and Product Analysis — ASME SA738 Grade C (typical Table 1 limits)
| Element | Heat Analysis (%) | Product Analysis (%) |
|---|---|---|
| Carbon (C), max | 0.20 | Per Table 1 of the named edition |
| Manganese (Mn), ≤40 mm | 1.50 max | 1.62 max |
| Manganese (Mn), 40–65 mm | 1.50 max | 1.62 max |
| Manganese (Mn), >65 mm | 1.60 max | Per Table 1 of the named edition |
| Phosphorus (P), max | Per Table 1 of the named edition | Per Table 1 of the named edition |
| Sulfur (S), max | Per Table 1 of the named edition | Per Table 1 of the named edition |
| Silicon, copper, nickel, chromium, molybdenum, vanadium, niobium | Per Table 1 of the named edition | Per Table 1 of the named edition |
Grade A carbon heat is 0.24% max. Grade B manganese is a 0.90–1.50 range, not only a maximum. Grade D carbon heat is 0.10% max. Do not ship Grade A or Grade B as Grade C. Vacuum carbon-deoxidized steel under S17 may replace part of the table when specified.
SHH STEEL reports heat analysis on every certificate and product analysis when SA-20 requires it. If a Houston, Rotterdam or Jebel Ali specification tightens phosphorus or sulfur, write that on the order.
Mechanical Properties
Grade C is the 80 ksi tensile class.
Tensile Requirements — ASME SA738 Grade C (typical Table 2, ≤50 mm)
| Property | Requirement |
|---|---|
| Yield strength, min | 345 MPa (50 ksi) |
| Tensile strength | 550 – 690 MPa (80 – 100 ksi) |
| Elongation in 50 mm, min | Per Table 2 of the named edition |
| Density | 7.85 g/cm³ |
| Hardness | Not a default substitute for tensile |
Tensile columns can change with thickness in Table 2. Confirm the ordered thickness against the named edition. Grade A is 515–655 MPa tensile. Grade B is 585–705 MPa tensile. Grade E is 620–760 MPa tensile. Do not stamp Grade C as Grade B because a coupon came in high.
Density is 7.85 g/cm³. Notch toughness is commonly added for moderate and lower temperature service. Write the temperature, energy, location and orientation. Simulated PWHT is common because QT plate will see a shop heat cycle after welding.
Material Comparison
| Grade | Route | Strength idea | Swap? |
|---|---|---|---|
| SA738 Grade A | Heat-treated C-Mn-Si | 310 / 515–655 | No |
| SA738 Grade B | QT C-Mn-Si | 415 / 585–705 | No |
| SA738 Gr.C | QT C-Mn-Si | 345 / 550–690, QT all t | This page |
| SA738 Grade D / E | QT C-Mn-Si | 85 / 90 ksi class, thinner cap | No |
| SA516 Gr.70 | C-Mn-Si vessel | 260 / 485–620 | No |
| ASME SA612 | High-strength C-Mn-Si | 345 yield, different book | No |
| SA737 Grade B | Normalized HSLA | 345 / 485–620 | No |
| SA537 Cl.1 | Heat-treated carbon | Different book | No |
SA203 Gr.A, SA225 Gr.C and SA455 steel plate are also vessel plates. None of them is ASME SA738 GR.C.
Heat-Treated C-Mn-Si Vessel Service
ASME SA738 Grade C / ASME SA738 GR.C is selected when the vessel wants quenched-and-tempered C-Mn-Si at the 80 ksi tensile class for moderate and lower temperature welded service. Typical equipment is storage vessels, process drums and other Section VIII work written to SA-738 Grade C. Allowable stress comes from ASME Section II Part D after the Code lists this Grade.
SHH STEEL supplies this plate to fabricators in the United States, Europe, the Middle East and Southeast Asia. It is not nickel low-temp plate like SA203 Gr.D or SA203 Gr.E. It is not QT Ni-Cr-Mo like SA543. It is not SA302 Gr.C. Stainless inquiries belong on ASME SA240 or ASTM A240.
Do not treat Grade C as normalize-only Grade A. Grade C is QT at every thickness. Do not treat Grade C as Grade B containment plate. Grade B is the 85 ksi class.
Weldability
SA738 Gr.C is killed C-Mn-Si at the 80 ksi class after quench and temper. Welding is Code welding.
Qualify procedures to ASME Section IX. Use consumables written for 550–690 MPa tensile QT carbon, not a SA516 Gr.70 procedure copied across, and not a SA543 Ni-Cr-Mo procedure. Hydrogen control, preheat and PWHT follow the qualified procedure and the vessel specification.
Do not copy a SA387 Gr.12 Cl.2 procedure onto SA738 Grade C. The fabricator owns the WPS. SHH STEEL can share mill heat data for that review, including packages prepared for US, EU or Middle East inspectors.
Heat Treatment
Grade C plates in all thicknesses shall be quenched and tempered. When plates are tempered, the minimum tempering temperature is 595 °C (1100 °F). Print austenitizing and tempering temperatures on the certificate when the mill record carries them.
Do not apply the Grade A rule (QT only above 65 mm) to Grade C. Do not ship Grade C as normalized carbon and call it heat-treated.
If the vessel will see PWHT, test coupons shall follow a simulated cycle when the order names it. Special heat treatment, extra simulation or third-party hold points add time. Plan about two months when those extras are on the order.
Delivery Condition
Usual delivery from SHH STEEL is quenched-and-tempered ASME SA738 Grade C / ASME SA738 GR.C plate.
The certificate lists ASME SA738 Grade C and, when dual certified, ASTM A738 Grade C; heat number; heat analysis; product analysis when ordered; tensile results to the Grade C table; QT statement; impact when ordered. Certificates may be EN 10204 3.1 or EN 10204 3.2.
Surface is mill scale unless the order names shot blast, paint or machine allowance. Cutting, beveling and nest sizes belong on the purchase order.
Dimensions
Usual supply range from SHH STEEL for SA738 Gr.C heat-treated vessel plate:
- Thickness: commonly 8 mm – 150 mm. Current practice normally limits Grade C to about 150 mm
- Width: 1500 mm – 4000 mm
- Length: 3000 mm – 12000 mm
- Cut-to-length shells, heads and nest sizes inside those limits
Structural sizes belong on EN 10025-2 or JIS G3106. Weathering plate belongs on EN 10025-5 or Corten A/B. Fine-grain structural belongs on EN 10025-3 or EN 10025-4. QT structural belongs on EN 10025-6.
Tolerances
Dimensional limits follow ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances, not structural-plate tolerances from ASTM A36/A36M. UT to A435 / A577 / A578 is added when the order names it.
Repair welding of surface defects follows SA-20 rules unless the order forbids repair.
Supplementary Requirements
Most export ASME SA738 Grade C / ASME SA738 GR.C orders add extras. SHH STEEL does not assume them.
Charpy details. Temperature, energy, location and orientation.
Simulated PWHT. Same-heat coupons follow the vessel cycle when named.
NDE. UT to A435 / A577 / A578.
Vacuum carbon deoxidation (S17). When specified.
Through-thickness / Z-direction testing. When the drawing names it.
Third-party. EN 10204 3.2, with inspectors arranged for US, European or Middle East documentation packages.
Equivalent Material Grades
These names are project-comparison grades. They are not automatic substitutes.
| Designation | Standard / region | Notes |
|---|---|---|
| ASME SA738 Grade C / ASME SA738 GR.C | ASME SA-738/SA-738M | Code name on this page |
| ASTM A738 Grade C | ASTM A738/A738M | Companion US product spec |
| SA738 Grade A / B / D / E | SA-738 | Other strength classes |
| SA537 Cl.1 | SA-537 | Related heat-treated carbon |
| P355NH / P355NL / P460 related | EN 10028 | European comparison only |
| SPV355 / SPV410 related | JIS G3115 | Japanese vessel comparison |
| Q345R / Q370R related | GB/T 713 | Chinese vessel comparison |
| SA516 Gr.70 | SA-516 | Related carbon vessel, different book |
| ASTM A516 | A516 family | Related carbon vessel family |
DIN 17100, ASME SA515 and ASTM A285 are not SA738 Grade C.
Applications
| Industry | Typical components |
|---|---|
| Heat-treated welded vessels | ASME SA738 Grade C shells and ASME SA738 GR.C heads |
| Moderate and lower temperature equipment | SA738 Gr.C courses |
| Dual-certified export | SA738 / A738 Grade C plate from SHH STEEL |
| Fabrication | SA738 Gr.C cut to nest sizes |
Ship plate inquiries belong on shipbuilding steel plates or BV Rules. Weathering inquiries belong on weathering steel plates. Stainless inquiries belong on stainless steel products, JIS G4305 or AISI stainless.
Other vessel comparisons: SA203 Gr.B, SA302 Gr.A, A516 Grade 70, SA533 Type C Cl.2, SA517 Gr.P.
Global Delivery & Markets
SHH STEEL is a global steel mill sourcing partner with mill partnerships in China. We supply ASTM, ASME, EN and JIS steel to the USA, Europe, Middle East and Southeast Asia. Origin is mill-direct, China origin. We do not treat SA738 Grade C as an Asia-only stock item. Inquiry packages are written for fabricators and EPC buyers in Houston, Rotterdam, Antwerp, Jebel Ali, Dammam, Singapore and surrounding ports.
Typical trade terms:
- FOB Shanghai
- CIF Houston
- CIF Rotterdam
- CIF Jebel Ali
- Other CIF / CFR ports on request (Los Angeles, New York, Hamburg, Genoa, Jeddah, Mundra, Ho Chi Minh)
Typical lead time for ASME SA738 Grade C / ASME SA738 GR.C:
- Ex-stock / ready plate: about 5–7 days after order confirmation, subject to actual warehouse size and cutting
- Mill rolling, standard QT: about 45 days
- Special heat treatment, simulated PWHT, 3.2 hold or extra NDE: about 2 months
Documents travel with the cargo: mill certificate, packing list, commercial invoice, bill of lading, and EN 10204 3.1 or 3.2 as ordered. Third-party inspection can be arranged before loading for US, European or Middle East projects. Packing is seaworthy, with edge protection and marking in English as specified on the order.
If the buyer needs a dual ASTM A738 / ASME SA738 stamp for a Section VIII vessel in the United States, say so on the inquiry. If the buyer needs a PED / 3.2 file for Europe, say so on the inquiry. Do not assume a domestic Chinese certificate format will pass at destination.
Why Choose SHH STEEL
SHH STEEL is a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin). We supply ASTM / EN / JIS steel to the USA, Europe, the Middle East and Southeast Asia. On ASME SA738 Grade C / ASME SA738 GR.C that means mill pricing, dual SA738/A738 marking, Grade C chemistry reported, recorded quench and temper, tensile results at 345 MPa yield and 550–690 MPa tensile, 3.1 as standard and 3.2 when specified. Trade terms include FOB Shanghai and CIF Houston / Rotterdam / Jebel Ali.
We keep the Grade on the order. Grade C is not Grade A and is not Grade B. Grade C is QT at every thickness. SA738 Grade C is not SA516 Grade 70. SA738 Grade C is not SA737 Grade C. SA738 is not SA387 Gr.22 Cl.2. If the drawing names Grade B containment extras, we will not ship Grade C and call it close.
Company scope: global steel mill sourcing partner – SHH STEEL.
FAQ
- What names are used for ASME SA738 Grade C / ASME SA738 GR.C?Buyers write ASME SA738 Grade C, ASME SA738 GR.C, SA738 Gr.C, SA738GRC, SA-738 Grade C, A738 Grade C and ASTM A738 Gr.C. SHH STEEL prints the wording on the purchase order.
- Is ASME SA738 Grade C the same as ASTM A738 Grade C?Chemistry and tensile limits match. ASME SA-738 is the Code version. ASTM A738 is the product spec. SHH STEEL dual-certifies both names when the vessel must be stamped in the United States or elsewhere.
- What is the yield strength of SA738 Gr.C?345 MPa minimum. Tensile is 550–690 MPa on the usual thickness column. Confirm Table 2 for the ordered thickness.
- Must ASME SA738 GR.C be quenched and tempered?Yes. Grade C is QT in all thicknesses. Grade A is QT only above 65 mm.
- How is ASME SA738 Grade C different from Grade B?Grade C is the 80 ksi class at 345 MPa yield. Grade B is the 85 ksi class at 415 MPa yield. Both are QT in all thicknesses.
- Can SHH STEEL ship ASME SA738 Grade C outside Asia?Yes. SHH STEEL is a global steel mill sourcing partner. We supply this plate to the USA, Europe, the Middle East and Southeast Asia on FOB Shanghai or CIF Houston / Rotterdam / Jebel Ali.
- What is the delivery time for SA738 Gr.C?Ex-stock about 5–7 days. Standard mill QT about 45 days. Special heat treatment, simulated PWHT or 3.2 inspection about 2 months.
- Can welding of SA738 Grade C be qualified to ASME Section IX?Yes. Use a WPS written for this QT C-Mn-Si tensile band. The fabricator owns the procedure.
- Can SHH STEEL issue EN 10204 3.2 for ASME SA738 Grade C?Yes. EN 10204 3.1 is standard. EN 10204 3.2 is arranged when written on the order.
Conclusion
ASME SA738 Grade C Steel Plate, also searched as ASME SA738 GR.C, is quenched-and-tempered C-Mn-Si plate under ASME SA-738/SA-738M for moderate and lower temperature welded vessels, at 345 MPa yield and 550–690 MPa tensile. Whether the inquiry says ASME SA738 Grade C, ASME SA738 GR.C, SA738 Gr.C or A738 Grade C, SHH STEEL as a global steel mill sourcing partner and steel manufacturer & exporter (mill-direct, China origin) supplies plate with Grade C chemistry, recorded QT delivery, and EN 10204 3.1 or 3.2 certification.
SHH STEEL supplies ASME SA738 Grade C / SA738 Gr.C Heat-Treated Vessel Plate to the USA, Europe, the Middle East and Southeast Asia for ASME Section VIII work that actually names this Grade. FOB Shanghai / CIF Houston / Rotterdam / Jebel Ali.
Contact SHH STEEL for mill rolling, stock inquiry, dual SA738/A738 marking, impact testing, 3.2 inspection or a quotation.
ASME SA738 Grade C Steel Plate, ASME SA738 GR.C, SA738 Gr.C, SA738GRC, SA-738 Grade C, A738 Grade C, heat-treated vessel plate, global steel mill sourcing partner SHH STEEL
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