ASME SA737 Grade C Steel Plate | SA737 Gr.C HSLA Vessel Plate

ASME SA737 Grade C, also written ASME SA737 GR.C, is high-strength low-alloy steel plate under ASME SA-737/SA-737M. The specification is identical with ASTM A737/A737M. It covers two grades only — Grade B and Grade C — for welded pressure vessels and piping components where high strength and improved toughness are required. There is no Grade A. Grade C provides 415 MPa yield and 550–690 MPa tensile. Grade B provides 345 MPa yield and 485–620 MPa tensile. 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-737/SA-737M and shipped to buyers in the USA, Europe, Middle East and Southeast Asia.

Buyers write ASME SA737 Grade C, ASME SA737 GR.C, SA737 Gr.C, SA737GRC, SA-737 Grade C, SA 737 Gr C, A737 Grade C and ASTM A737 Gr.C. A purchase order that only says “SA737” is incomplete. A purchase order that writes “SA737 Grade A” invents a grade the book does not list. This page is not SA516 Gr.70. Grade 70 is carbon vessel plate at 260 MPa yield. SA737 Grade C is HSLA at 415 MPa yield. It is not SA612. It is not QT Ni-Cr-Mo like SA543. It is not SA662 Grade C, even though the letters match.

The steel shall be killed and shall conform to the fine austenitic grain size requirement of ASME SA-20 / ASTM A20. Current practice normally limits thickness to about 100 mm. Grade C in the as-rolled condition is sensitive to cracking during flame cutting, transit and handling, particularly over 50 mm. Plates should not be shipped as-rolled except by mutual agreement. Dual marking SA737 / A737 Grade C is available. Certificates can be EN 10204 3.1 or 3.2. Company scope: global steel mill sourcing partner – SHH STEEL.

This plate sits in pressure vessel steel plates and high strength low alloy 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.

ASME SA737 Grade C / ASME SA737 GR.C uses the Grade C column. Grade C is the vanadium HSLA line. Grade B is the niobium line.

Heat Analysis and Product Analysis — ASME SA737 Grade C (typical Table 1 limits)

Grade B carbon heat is 0.20% max and niobium is the microalloy. Do not ship 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, including V, 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.

Grade C is the 60 ksi yield line.

Tensile Requirements — ASME SA737 Grade C

Grade B is 345 MPa yield and 485–620 MPa tensile, still 18% / 23% elongation. Do not stamp Grade B as Grade C because a coupon came in high. Do not treat 415 MPa yield as a free swap with SA517 Gr.A or other QT alloy books.

Density is 7.85 g/cm³. Notch toughness is commonly added for vessel and piping service. Write the temperature, energy, location and orientation. Through-thickness properties and UT matter more as thickness approaches 100 mm.

SA203 Gr.B, SA225 Gr.D and SA455 steel plate are also vessel plates. None of them is ASME SA737 GR.C.

ASME SA737 Grade C / ASME SA737 GR.C is selected when the vessel or piping component wants the higher HSLA line and improved toughness in a killed, fine-grain plate. Typical equipment is welded pressure vessels, drums and piping components written to SA-737 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 alloy like SA543. It is not SA302 Gr.C. Stainless inquiries belong on ASME SA240 or ASTM A240.

Do not treat this plate as structural high strength low alloy plates cut from A572. A572 is not SA-20 vessel plate. SA737 Grade C is a vessel specification. Do not ship thick Grade C as-rolled and hope the shop flame-cuts it safely.

SA737 Gr.C is killed HSLA at 415 MPa yield. Welding is Code welding.

Qualify procedures to ASME Section IX. Use consumables written for 550–690 MPa tensile HSLA, not a Grade B procedure copied up, not a plain SA516 Gr.70 procedure, and not a QT alloy procedure from SA543. Vanadium belongs in the WPS review. Hydrogen control, preheat and PWHT follow the qualified procedure and the vessel specification.

Do not copy a SA387 Gr.12 Cl.2 procedure onto SA737 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.

Plates shall be normalized. Heat to a temperature that produces an austenitic structure, not exceeding 925 °C (1700 °F), hold long enough for uniform heat, then cool in air. If the purchaser agrees, cooling faster than air cooling is permitted to improve strength or toughness, provided the plates are subsequently tempered between 595 °C and 705 °C (1100–1300 °F).

Do not ship Grade C as-rolled except by mutual agreement. The specification states that Grade C in the as-rolled condition is sensitive to cracking during flame cutting, transit and handling, particularly over 50 mm.

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.

Usual delivery from SHH STEEL is normalized ASME SA737 Grade C / ASME SA737 GR.C plate.

The certificate lists ASME SA737 Grade C and, when dual certified, ASTM A737 Grade C; heat number; heat analysis including V; product analysis when ordered; tensile results to the Grade C table; normalize 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.

Usual supply range from SHH STEEL for SA737 Gr.C HSLA vessel plate:

• Thickness: commonly 8 mm – 100 mm. Current practice normally limits this specification to about 100 mm. Over 50 mm, as-rolled handling is a cracking risk
• Width: 1500 mm – 4000 mm
• Length: 3000 mm – 12000 mm
• Cut-to-length shells, heads, piping components 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.

Dimensional limits follow ASME SA-20. Thickness, width, length, flatness and camber are vessel-plate tolerances, not structural-plate tolerances from ASTM A36/A36M or ASTM A572/A572M. 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.

Most export ASME SA737 Grade C / ASME SA737 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.

These names are project-comparison grades. They are not automatic substitutes.

DIN 17100 and ASTM A285 are not SA737 Grade C.

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.A, SA302 Gr.A, A516 Grade 70, SA533 Type C Cl.1, SA517 Gr.P.

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 SA737 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 SA737 Grade C / ASME SA737 GR.C:

• Ex-stock / ready plate: about 5–7 days after order confirmation, subject to actual warehouse size and cutting
• Mill rolling, standard normalize: 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 A737 / ASME SA737 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.

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 SA737 Grade C / ASME SA737 GR.C that means mill pricing, dual SA737/A737 marking, Grade C chemistry with V reported, recorded normalize, tensile results at 415 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 B. There is no Grade A. SA737 Grade C is not SA662 Grade C. SA737 is not SA516 Grade 70. SA737 is not SA387 Gr.22 Cl.2. SA737 Grade C is not A572 Grade 60 structural plate. If the shop wants as-rolled Grade C over 50 mm, we will say the specification treats that as a cracking risk.

Company scope: global steel mill sourcing partner – SHH STEEL.

ASME SA737 Grade C Steel Plate, also searched as ASME SA737 GR.C, is HSLA plate under ASME SA-737/SA-737M for welded pressure vessels and piping, at 415 MPa yield and 550–690 MPa tensile. Whether the inquiry says ASME SA737 Grade C, ASME SA737 GR.C, SA737 Gr.C or A737 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 normalize, and EN 10204 3.1 or 3.2 certification.

SHH STEEL supplies ASME SA737 Grade C / SA737 Gr.C HSLA 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 SA737/A737 marking, impact testing, 3.2 inspection or a quotation.

ASME SA737 Grade C Steel Plate, ASME SA737 GR.C, SA737 Gr.C, SA737GRC, SA-737 Grade C, A737 Grade C, HSLA vessel plate, global steel mill sourcing partner SHH STEEL