CCS EH420 (also written CCS E420, CCS/E420, CCS Grade E420 or EH420 steel plate) is a high-strength steel for welded marine and offshore structures certified by the China Classification Society (CCS) to CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Section 4 (High Strength Steels for Welded Structures). The number 420 is the minimum yield strength in MPa (up to 50 mm), tensile strength is 520–680 MPa, and the letter E sets the Charpy V-notch test temperature of −40°C. It is delivered normalized/normalized-rolled (N/NR), thermo-mechanically rolled (TM) or quenched and tempered (QT) and corresponds to grade EH420 in IACS UR W16.

Gangsteel, a steel plate exporter, supplies CCS EH420 plate with CCS class certificates; the requirements below are taken directly from the current CCS rules.

Related CCS grades: CCS AH420 steel plate, CCS DH420 steel plate, CCS FH420 steel plate, CCS EH460 steel plate.

CCS EH420 chemical composition

CCS EH420 chemical composition, heat (ladle) analysis, % max unless stated, by delivery condition
ElementHeat analysis, N/NRHeat analysis, TMHeat analysis, QT
C≤ 0.18≤ 0.14≤ 0.18
Mn1.00–1.701.00–1.70≤ 1.70
Si≤ 0.60≤ 0.60≤ 0.80
P≤ 0.025≤ 0.020≤ 0.020
S≤ 0.020≤ 0.010≤ 0.010
Al (total)≥ 0.02≥ 0.02≥ 0.018
Nb≤ 0.05≤ 0.05≤ 0.06
V≤ 0.20≤ 0.12≤ 0.12
Ti≤ 0.05≤ 0.05≤ 0.05
Ni≤ 0.80≤ 2.00≤ 2.00
Cu≤ 0.55≤ 0.55≤ 0.50
Cr≤ 0.30≤ 0.50≤ 1.50
Mo≤ 0.10≤ 0.50≤ 0.70
N≤ 0.025≤ 0.025≤ 0.015

 

Source: CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Table 3.4.3.2 (same values as IACS UR W16 Rev.3). Notes: Nb+V+Ti ≤ 0.26% and Mo+Cr ≤ 0.65% (not applicable to QT); total Al/N ≥ 2:1 unless other nitrogen-binding elements are used; Ni above 2.00% may be approved by CCS; boron, if added, ≤ 0.005%. 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 EH420 mechanical properties and impact test

CCS EH420 tensile and Charpy V-notch requirements
Thickness (mm)Yield ReH min (MPa)Tensile Rm (MPa)
3 ≤ t ≤ 50420520–680
50 < t ≤ 100390520–680
100 < t ≤ 250365470–650
CCS EH420 elongation and impact energy
Elongation A5 min, T (%)Elongation A5 min, L (%)Charpy test temp.KV avg min, T (J)KV avg min, L (J)
1921−40°C2842

Source: CCS Rules for Materials and Welding (2024), Part 1, Chapter 3, Table 3.4.7.4. Plates over 600 mm wide are impact tested transversely (T value applies). For N/NR and TM plates one impact test is taken from each piece; for QT plates from each individually heat-treated piece. Above 50 mm, impact specimens are taken at t/4 and t/2.

CCS EH420 maximum carbon equivalent (plates)
Delivery conditionCeq t ≤ 50 mmCeq 50 < t ≤ 100 mmCeq 100 < t ≤ 250 mmCETPcm
N/NR0.460.480.52n/an/a
TM0.430.450.47n/an/a
QT0.450.470.49n/an/a

Table 3.4.3.4. Ceq = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15; CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40 (H460 and above, at the mill’s option); Pcm may be used for TM and QT steels with C ≤ 0.12%. n/a = not applicable.

CCS EH420 thickness range and delivery condition

CCS EH420 maximum plate thickness by delivery condition
Delivery conditionMax plate thickness (mm)
N250
NR150
TM150
QT150

Table 3.4.6.2. Thicker plates (N over 250 mm, QT over 150 mm) need special consideration by CCS. Yield and tensile requirements fall in steps above 50 mm and 100 mm, as shown in the table above.

CCS EH420 equivalent grades

CCS EH420 equivalent grades of other classification societies
Standard / societyEquivalent grade
IACS UR W16EH420
ABSAB/EQ43
DNVVL E420
LRLR EH42
ASTM A131no equivalent (A131 stops at the 40 strength level)

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 EH420 FAQ

Is CCS E420 the same as CCS EH420?

Yes. CCS lists the grade as EH420; E420 is a common shorthand for the same steel.

What is the yield strength of CCS EH420?

Minimum 420 MPa up to 50 mm, 390 MPa for 50–100 mm and 365 MPa for 100–250 mm. Tensile strength is 520–680 MPa (up to 100 mm).

What is the impact test temperature of CCS EH420?

−40°C, with a minimum average of 28 J transverse or 42 J longitudinal.

What is CCS EH420 equivalent to?

EH420 in IACS UR W16, ABS AB/EQ43, DNV VL E420 and LR EH42. ASTM A131 has no grade at this strength.

How is CCS EH420 supplied?

Normalized/normalized-rolled (N/NR), TM or QT. The chemistry and carbon-equivalent limits depend on the delivery condition.

What is the maximum thickness of CCS EH420 plate?

Up to 150 mm in TM or QT condition (N up to 250 mm, NR up to 150 mm); thicker plates need special consideration by CCS.

What is the CEV of CCS EH420?

Ceq maximum for plates up to 50 mm is 0.46% (N/NR), 0.43% (TM), 0.45% (QT). Higher limits apply to thicker plates.

What is the difference between CCS EH420 and the A, D, E and F grades of the same strength?

The strength requirements are identical; only the Charpy test temperature changes (0, −20, −40 or −60°C), and E/F grades have tighter P and S limits.

Equivalent steel grade of CCS/E420

DNV

GL

LR

BV

ABS

NK

KR

RINA

NV E420

GL-E420

LR/EH42

BV/E420

ABS/EQ43

K E43

R E43

RI/E420

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

Related steel grades: CCS/A420, CCS/D420, CCS/E620,CCS/F550

 

CCS Steel Plate Grade

General Strength

CCS/A

CCS/B

CCS/D

CCS/E

High Strength

CCS/A32

CCS/D32

CCS/E32

CCS/F32

CCS/A36

CCS/D36

CCS/E36

CCS/F36

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CCS/E40

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Extra Strength

CCS/A420

CCS/D420

CCS/E420

CCS/F420

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CCS/A500

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CCS/F500

CCS/A550

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CCS/E550

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