Description: BBN steel is a well-known steel manufacturer and service provider in China, ASTM A131 AH36 steel plate is our superior product, we are favored by customers with high quality, competitive price and excellent service
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ASTM A131 AH36 is the most widely ordered grade of the high-strength hull structural steel family defined by ASTM A131 / A131M. It carries a minimum yield strength of 355 MPa (51 KSI) with a tensile range of 490–620 MPa, and it is Charpy V-notch impact tested at 0 °C — the temperature class that makes it the standard choice for hull structures, decks and offshore members on temperate and tropical service routes.
AH36 is supplied as-rolled across the full thickness range, with normalized and control-rolled conditions available where the order or the class rules call for them. Because the grade is produced on a route approved by the major IACS classification societies, the same plate can be released with the stamp and mill test certificate of the society named in your order.
ASTM A131 / A131M, Marine Classification Society Certified
Plate Type
Hot Rolled Shipbuilding Structural Steel Plate
Thickness Range
5 mm – 150 mm full range available
Width Range
1800 mm – 5500 mm
Length Range
3000 mm – 18000 mm custom sizes negotiable
Delivery Condition
As RolledNormalizedControl Rolled
Main Application
Ship hull structure, offshore platforms, marine engineering equipment, deck and load-bearing parts
MOQ
1 Ton / Negotiable
Delivery Time
In-stock: 3–7 days; custom production: 10–30 working days
Quantity Schedule
1–10 t: 5 days · 10–50 t: 10 days · >50 t: negotiable
Payment Terms
L/C, T/T, D/P, Western Union, Paypal, Money Gram
Certification
MTC, EN 10204 3.1, ABS / CCS / LR / DNV third-party ship inspection certificate
Note: the size range above is the published rolling and stock range — not every thickness, width and length combination can be produced on every campaign. Lead time counts from order confirmation and depends on the mill programme; the quantity schedule and the payment terms are the ones published on this product page. Certificates are issued for the society named in the purchase order — see section 03 before you write it.
02Reading the Designation
The name splits into three parts. Only the number carries a strength value; the letter is a temperature class, not a quality ranking — getting these two apart is what keeps an AH36 order from being substituted with the wrong grade.
Segment
What It Means
A
Impact toughness class — Charpy V-notch testing is carried out at 0 °C
H
Higher strength — marks the grade as part of the high-strength hull family rather than the 235 MPa ordinary-strength A / B / D / E group
36
Strength class — 36 kgf/mm², i.e. 355 MPa minimum yield. The number is a strength level, not a carbon content or a quality code
Grade Letter
Charpy V-notch Test Temperature
A (this page)
0 °C
D
−20 °C
E
−40 °C
F
−60 °C
Note: the four letters are four toughness classes of the same 355 MPa strength level — AH36, DH36, EH36 and FH36 have identical yield and tensile requirements and differ only in the impact test temperature. Pick the letter from the lowest design service temperature of the member, never from strength: a colder letter costs more alloy and more mill control, but buys no extra yield. The strength number follows the same logic one level up and down — 32 is the 315 MPa class and 40 is the 390 MPa class.
03Classification Society & Equivalent Grades
Hull structural steel designations are harmonised across the IACS member societies, so the toughness letter and the strength number mean the same thing everywhere. What changes is the string each society stamps on the plate and prints on its certificate — the table below is what to write in the enquiry for the 0 °C / 355 MPa class covered by this page.
Classification Society
Designation Used for This Grade
ABS — American Bureau of Shipping
ABS AH36 (also written AB/AH36)
LR — Lloyd's Register
LR AH36
DNV — Det Norske Veritas
DNV A36 (also written NV A36) — written without the H
BV — Bureau Veritas
BV AH36
CCS — China Classification Society
CCS AH36
NK — Nippon Kaiji Kyokai (ClassNK)
KA36 — the K prefix replaces the leading A/D/E/F
KR — Korean Register of Shipping
KR AH36
RINA — Registro Italiano Navale
RINA AH36
GL — Germanischer Lloyd
GL AH36 — administered by DNV since the 2013 merger
RS — Russian Maritime Register of Shipping
Confirmed on request at the enquiry stage
Other Standard System
Nearest Grade
Chinese GB 712
AH36
EN standard
S355NL
JIS standard
SM490B
Note: three traps worth knowing before the enquiry goes out. (1) DNV writes this class as A36 without the H — DNV E36 is the −40 °C grade, so mapping "ABS AH36" to "DNV E36" is not a like-for-like substitution; the 0 °C counterpart of ABS AH36 is DNV A36. (2) ClassNK uses a K prefix — KA36 / KD36 / KE36, where the letter after K is still the toughness class. (3) Germanischer Lloyd merged into DNV in 2013, so GL notation is issued from the DNV route. One production route can be approved by several societies, and the same plate can be re-stamped when a vessel changes flag, but dual or multiple certification must be requested at the enquiry and written into the purchase order — it cannot be added after the plates have shipped. Equivalence across standard systems is approximate: GB 712 AH36, S355NL and SM490B are close neighbours, not automatic substitutes, and substitution needs class approval plus confirmation on the MTC.
04Chemical Composition
The limits below are the specified values per ASTM A131 / A131M for the AH36 high-strength class — a low-carbon, manganese-strengthened analysis with niobium, vanadium and titanium as grain-refining and precipitation-strengthening additions.
Element
Content %
Element
Content % (Max)
C (Carbon)
0.18 (Max)
Nb (Niobium)
0.02 – 0.05
Si (Silicon)
0.10 – 0.50
V (Vanadium)
0.05 – 0.10
Mn (Manganese)
0.90 – 1.60
Ti (Titanium)
0.02
P (Phosphorus)
0.035 (Max)
Cu (Copper)
0.35
S (Sulfur)
0.035 (Max)
Cr (Chromium)
0.20
Al (Aluminium)
>0.015 (Min.)
Ni (Nickel)
0.40
N (Nitrogen)
—
Mo (Molybdenum)
0.08
Note: these are specified limits, not a typical analysis — the actual heat analysis of each plate, including the carbon equivalent, is stated on its Mill Test Certificate (MTC / EN 10204 3.1) supplied with delivery. The aluminium figure is acid-soluble aluminium for grain refinement; niobium, vanadium and titanium are micro-alloying additions that do the strengthening work alongside manganese. Where a source sets no limit for an element (nitrogen here), the cell is left as — rather than filled from another grade's table.
05Mechanical Properties
Room-temperature mechanical properties and the 0 °C Charpy V-notch impact parameters of ASTM A131 AH36 high-strength hull steel, by thickness bracket.
Note: three things to check against the MTC rather than this page. (1) Impact energy above 50 mm is not given in the source table — it follows the applicable classification society rules and the order agreement, so the two energy cells for the thicker brackets are left as — instead of being carried over from another bracket. (2) Direction of the energy values: the source table labels Energy 1 as transverse (34 J) and Energy 2 as longitudinal (24 J). ABS rules and most supplier data sheets assign the higher 34 J to the longitudinal direction and 24 J to the transverse one, and the BBN grade table for this same steel prints Energy 1 = 24 J / Energy 2 = 34 J. It is the same pair of numbers with the directions swapped, so read the direction off the MTC and the class rules named in your order, not off a product page. (3) Elongation: published as 22 % here, while several sources — including the ABS reference matrix and the BBN grade table — quote 21 % on a 50 mm gauge length. Confirm the gauge length together with the value.
06Application Fields
With a 355 MPa minimum yield, AH36 lets a designer drop one thickness step below ordinary-strength Grade A or D plate — that weight saving is the reason it is the default high-strength grade for hull and topside structure in temperate service.
Shipbuilding Industry
Hull structural plates, deck plates, bulkhead plates and ship load-bearing components on bulk carriers, container ships, tankers and general cargo vessels.
Offshore Engineering
Offshore oil & gas platforms, marine wind power supporting structures and offshore equipment bases.
Marine Facilities
Port machinery structures, marine engineering vessels, floating facilities and auxiliary marine steel structures.
Deck & Load-Bearing Structure
Deck plating, stringers, hatch coamings and crane foundations where the weight saved against 235 MPa plate pays back in cargo capacity.
Ship Repair & Conversion
Replacement plate for repair and conversion work, where the new plate has to match the class-approved grade of the original structure.
07Processing, Inspection & Supply
Full-spec AH36 shipbuilding steel plates with complete ship inspection certificates — bulk wholesale, custom deep processing and one-stop marine steel procurement for global shipyard and offshore engineering clients.
1
In-Stock Supply
Full-size A131 AH36 plates 5–150 mm in stock, delivered within 3–7 days.
2
Custom Deep Processing
Custom cutting, bending, welding, surface treatment and precision sizing, 10–30 working days.
3
Ship Inspection
ABS / CCS / LR / DNV third-party ship inspection certificates with MTC and EN 10204 3.1.
4
One-Stop Procurement
Bulk wholesale and consolidated marine steel sourcing for global shipyard projects.
Note: ultrasonic testing, Z-direction testing (Z15 / Z25 / Z35), additional Charpy brackets, shot blasting and shop primer, and third-party inspection beyond the named class society are all order options — they are arranged on request and priced against the enquiry, not included by default. Name them in the purchase order together with the society, so they appear on the certificate.
08Other Common ASTM A131 Grades We Supply
AH36 is one grade inside the ASTM A131 / A131M hull steel family. When the design calls for a different strength level or a different impact test temperature — or simply for a more economical plate on a colder route — the grades below are the ones most often ordered alongside it. Every grade name is a link to its own product page.
Ordinary-Strength Hull Grades — Grade A / B / D / E
General-strength A131 hull steel for ship bodies, decks and superstructures: 235 MPa minimum yield, 400–520 MPa tensile and 21% minimum elongation. The required Charpy V-notch temperature drops as the grade letter advances — Grade B is tested at 0 °C, Grade D at −20 °C and Grade E at −40 °C, while Grade A carries no mandatory impact energy value in the standard.
Entry level of the A131 higher-strength hull steels: 315 MPa minimum yield and 440–590 MPa tensile. The prefix fixes the Charpy V-notch test temperature — AH at 0 °C, DH at −20 °C, EH at −40 °C and FH at −60 °C.
The 355 MPa minimum yield class with 490–620 MPa tensile strength — the four grades are identical in strength and differ only in the impact test temperature: AH at 0 °C, DH at −20 °C, EH at −40 °C, FH at −60 °C. This page is the AH (0 °C) member of the group.
Top of the A131 higher-strength range: 390 MPa minimum yield and 510–650 MPa tensile. Same prefix rule for the impact temperature, with FH40 adding −60 °C coverage for ice-class and arctic structures.
Rule of thumb: the number gives the yield level (32 → 315 MPa, 36 → 355 MPa, 40 → 390 MPa) and the letter gives the impact temperature (A 0 °C, D −20 °C, E −40 °C, F −60 °C). Pick the lowest combination your class rules allow — that is where the cost is.
Note: the figures above are the values published on each grade's own BBN product page and are meant for short-listing only. Actual yield and tensile values, elongation, impact test temperature and absorbed energy depend on plate thickness, delivery condition and the applicable classification society rules — always confirm against the purchase order and the MTC issued with each plate.
It is the strength class, expressed in kgf/mm² — 36 kgf/mm², i.e. a 355 MPa minimum yield strength (51 KSI in inch-pound units). It is not a carbon content, not a quality code and not a tensile value: the tensile range is 490–620 MPa. The letter in front of it carries no strength information at all — that is the impact test temperature, 0 °C for the A of AH36.
Q2AH36, DH36 or EH36 — which one do I need?
All three carry the same 355 MPa minimum yield and the same 490–620 MPa tensile range; the only difference is the Charpy V-notch test temperature — AH36 at 0 °C, DH36 at −20 °C, EH36 at −40 °C. Choose from the lowest design service temperature of the member, not from strength: specifying EH36 for a tropical route buys toughness you will never use, while specifying AH36 for a refrigerated cargo space or a high-latitude route can fail the class review. See section 02 for the four-letter ladder and section 08 for the sibling grades.
Q3Why does DNV write this grade as A36 instead of AH36?
Because the societies harmonised the meaning of the grade but not the printed string. DNV drops the H and writes the 0 °C / 355 MPa class as A36 (also seen as NV A36), while ABS, LR, BV, CCS, KR and RINA keep the H and write AH36; ClassNK uses a K prefix, KA36. The practical trap is the letter swap: DNV E36 is the −40 °C grade and corresponds to ABS EH36, not to ABS AH36. If a drawing says AH36 and the certificate is expected in DNV notation, write DNV A36 on the order. The full table is in section 03.
Q4Can one plate be certified by more than one classification society?
Yes — the same approved production route can be released by several IACS societies, and a plate can be re-stamped when a vessel changes flag or registry. But the societies you need must be named at the enquiry and written into the purchase order; a second certificate cannot be added after the plates have shipped. Say which society stamps the plates, which issues the certificate, and whether you also need third-party inspection such as SGS. GL notation is handled through DNV following the 2013 merger.
Q5Is the 34 J impact value transverse or longitudinal?
Read it off the MTC rather than off any product page. Our source table labels Energy 1 as transverse (34 J) and Energy 2 as longitudinal (24 J), but ABS rules and most supplier data sheets put the higher 34 J on the longitudinal specimen and 24 J on the transverse one, and the BBN grade table for this same steel prints Energy 1 = 24 J / Energy 2 = 34 J. It is one pair of numbers with the two directions swapped between sources — the physics does not change (a transverse specimen reads lower), only the labelling does. State the direction and the required energy in the order. See the note under section 05.
Q6What sizes can you supply, and how fast?
The published rolling and stock range is 5–150 mm thick, 1800–5500 mm wide and 3000–18000 mm long, with custom sizes negotiable — not every thickness, width and length combination is available on every campaign, so send the actual sizes with the enquiry. In-stock plate ships in 3–7 days; custom production runs 10–30 working days. The published quantity schedule is 1–10 t in 5 days, 10–50 t in 10 days and above 50 t negotiable; payment is by L/C, T/T, D/P, Western Union, Paypal or Money Gram. Every plate ships with an MTC to EN 10204 3.1 plus the certificate of the society named in the order.
Get Your ASTM A131 AH36 Steel Plate Quotation Now
Send us your thickness, width & length (or part drawings), quantity, impact test temperature and the classification society you need on the certificate. We will reply with stock status, price, delivery time and complete marine certification documents within 24 hours.
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