CCS AH40 Steel Plate – Properties, Chemistry & Equivalents

CCS AH40 (also written CCS/AH40, CCS Grade AH40, CCS A40 or AH40 steel plate) is a higher-strength hull structural steel plate certified by the China Classification Society (CCS) to CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Section 3. The figure 40 is the strength level (minimum yield 390 MPa, tensile 510–660 MPa) and the letter A sets the Charpy V-notch test temperature of 0°C. The steel is killed and fine-grain treated, and the grade corresponds to AH40 in IACS UR W11 and AH40 in ASTM A131.

Gangsteel, a steel plate exporter, supplies CCS AH40 plate with CCS class certificates; the requirements below are taken directly from the current CCS rules.

Related CCS grades: CCS DH40 steel plate, CCS EH40 steel plate, CCS FH40 steel plate, CCS AH32 steel plate, CCS AH36 steel plate.

CCS AH40 chemical composition

Source: CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Table 3.3.2.1. Al, Nb and V are grain-refining elements: when used in combination, the individual minimum contents do not apply. Total Al ≥ 0.020% may be reported instead of acid-soluble Al. TMCP plates must also meet the Ceq limits below. CCS specifies the chemical composition as a heat (ladle) analysis only; the Rules give no product (check) analysis tolerances for these plates, so no product-analysis column is shown. If a product analysis is required, agree the tolerances in the order.

CCS AH40 mechanical properties and impact test

Source: CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Table 3.3.4.3. L = longitudinal, T = transverse. Impact tests are normally made longitudinally; transverse values must be guaranteed by the mill.

Ceq = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15, from the ladle analysis (Table 3.3.2.3(1)). For non-TMCP plates a Ceq limit may be agreed.

CCS AH40 thickness range and delivery condition

The CCS rules for CCS AH40 cover plates and wide flats up to 150 mm thick (sections and bars up to 50 mm). The permitted supply condition (as-rolled, controlled rolled, normalized or TMCP, or QT above 50 mm) depends on thickness and on the grain-refining elements used; see Table 3.3.3.1. The required Charpy energy increases above 50 mm and again above 70 mm.

CCS AH40 equivalent grades

The IACS member societies use the same unified requirements, so these grades match in chemistry and properties. A plate still needs the certificate of the vessel’s own class society; one plate can carry dual or multiple class certification only when each society’s surveyor witnesses the tests.

CCS AH40 FAQ

What does AH40 mean?

A sets the toughness grade (Charpy test at 0°C), H means higher strength, and 40 is the strength level: minimum yield 390 MPa.

What is the yield strength of CCS AH40?

Minimum 390 MPa, tensile strength 510–660 MPa and minimum elongation 20%.

What is the impact test temperature of CCS AH40?

0°C. Minimum average energy is 39 J longitudinal / 26 J transverse up to 50 mm, 46/31 J for 50–70 mm and 55/37 J for 70–150 mm.

What is CCS AH40 equivalent to?

AH40 of IACS UR W11, ABS AB/AH40, DNV VL A40, LR and BV AH40, ASTM A131 AH40 and GB/T 712 AH40.

What is the difference between AH40, DH40, EH40 and FH40?

They share the same chemistry limits (FH has tighter C, P and S limits, an N limit and a higher Ni allowance) and the same strength. Only the Charpy test temperature changes: 0°C (A), −20°C (D), −40°C (E) and −60°C (F).

What is the difference between CCS AH40 and ABS AH40?

Both are the same IACS UR W11 grade, so in practice they are interchangeable technically; the difference is the class certificate.

What is the carbon equivalent (CEV) of CCS AH40?

For TMCP plates Ceq must not exceed 0.40% up to 50 mm, 0.42% for 50–100 mm and 0.45% for 100–150 mm. For other conditions a Ceq limit may be agreed with the buyer.

What thickness range does CCS cover for AH40?

Plates and wide flats up to 150 mm; sections and bars up to 50 mm.

If you need more stock steel plates in shipbuilding steel plate, please click warehouse sizes.

 Related steel grades: CCS/DH40, CCS/EH40, CCS/FH40, CCS/AH36

ASTM equivalent: ASTM A131 AH40 steel plate