LR GRADE D and LR/D Ship steel plate supplier

Gangsteel supplies LR Grade D (LR/D) normal-strength shipbuilding steel plate for hull and structural use specified to Lloyd’s Register. This official product page states the July 2022 LR Chapter 3 ladle-analysis and mechanical-acceptance requirements for this grade. Availability, dimensions and delivery condition are confirmed against the enquiry; none is implied as stock.

Numerical requirements on this page are transcribed from Lloyd’s Register, Rules for the Manufacture, Testing and Certification of Materials, July 2022, Chapter 3 Rolled Steel Plates, Strip, Sections and Bars, Chapter 3, Section 2 Normal strength steels for ship and other structural applications, including Tables 3.2.1, 3.2.2 and 3.2.3, together with the general requirements of Chapter 3, Section 1 (including 1.7 dimensional tolerances and 1.9 test material and mechanical tests). The text used is the official July 2022 Rules as published. The current 1 July 2026 Rules (LR-RU-002) are issued through Regs4ships and were not independently obtained for this page. Lloyd’s Register Class News 14/2026 states that IACS UR W11 Rev.10 amendments affecting Chapter 3, Sections 1, 2 and 3 are to be included in the 1 January 2027 version of these Rules. The figures below are July 2022 LR rule requirements for plate, not measured results for a particular heat. The edition named in the contract, the certificate and the attending surveyor govern any actual supply.

Grade Designation

Table 3.2.1 and Table 3.2.3 designate this normal-strength hull steel as Grade D. Commercial and documentation forms include LR Grade D (LR/D), as on this official product page. Section 2 covers Grades A, B, D and E (minimum yield 235 N/mm²), distinguished by deoxidation practice, chemistry and the Charpy V-notch impact-test requirements of Table 3.2.3.

Key Advantages of LR Grade D Steel Plate

LR Grade D (LR/D) is a weldable normal-strength hull structural steel in July 2022 LR Chapter 3, Section 2, Table 3.2.3 (minimum yield 235 N/mm²), with a −20 °C Charpy V-notch laboratory test class in Table 3.2.3. It is used for welded ship structural members where this LR grade is specified.

Chemical Composition (Ladle Analysis)

Table 3.2.1, chemical composition of ladle samples (2.2.1).

Element / requirement	Value	Notes
Deoxidation	For t ≤ 25 mm: killed. For t > 25 mm: killed and fine grain treated with aluminium.	Table 3.2.1.
C, max. (%)	0.21 max.	Table 3.2.1.
Mn (%)	0.60 min.	Table 3.2.1.
Si (%)	0.10–0.35	Table 3.2.1. Grade A and B are maxima only; Grades D and E are a range.
P, max. (%)	0.035 max.	Table 3.2.1.
S, max. (%)	0.035 max.	Table 3.2.1.
Al (acid soluble), min. (%)	0.015 min. (see note 4)	Required for Grades D and E. The total aluminium content may be determined instead, and is then not to be less than 0.020 % (note 4).
C + Mn/6, max. (%)	0.40	Carbon + 1/6 of the manganese content is not to exceed 0.40 % (Table 3.2.1, row spanning Grades A, B, D and E).

Ladle samples (2.2.1). The manufacturer’s declared analysis is accepted subject to occasional checks if required by the Surveyors (2.2.3). Note 1: for Grade A, rimmed steel may only be accepted for sections up to 12.5 mm, and is to be stated on the test certificate or shipping statement. Note 5: where additions of any other elements are made as part of the steel-making practice, the content is to be recorded. Table 3.2.1 does not set numeric residual Cu, Cr, Ni or Mo limits for these normal-strength grades; none is invented here. Small variations from Table 3.2.1 may be allowed for Grade E over 50 mm, or when any Grade is supplied in a TM condition, provided they are documented and approved in advance (2.2.2).

Mechanical Properties

Tensile specimens: where the finished width of plates and flats is greater than 600 mm, the principal axes are perpendicular to the final direction of rolling; for all other rolled products, parallel (1.9.6). Impact specimens: where both longitudinal and transverse properties are shown, only the longitudinal test is required unless otherwise specified; for plates and wide flats the manufacturer, by certifying the product, guarantees the transverse values, and the Surveyor may request a transverse test (1.9.8). Impact tests are not required when the nominal thickness is less than 6 mm (1.9.11). Impact temperatures in Table 3.2.3 are laboratory conditions, not approved minimum service temperatures.

Property	Requirement	Notes
Yield stress, min.	235 N/mm²	Table 3.2.3; all of Grades A, B, D and E.
Tensile strength	400–520 N/mm²	Table 3.2.3. For sections in Grade A, the upper limit may be exceeded at the discretion of the Surveyor (note 1).
Elongation (L = 5.65 √A), min.	22 %	Table 3.2.3. For full-thickness specimens 25 mm wide with L = 200 mm, note 2 gives minima by thickness: 14 % (t ≤ 5 mm), 16 % (5 < t ≤ 10), 17 % (10 < t ≤ 15), 18 % (15 < t ≤ 20), 19 % (20 < t ≤ 25), 20 % (25 < t ≤ 30), 21 % (30 < t ≤ 35), 22 % (35 < t ≤ 50).
Impact test temperature	−20 °C	Laboratory test condition only, not an approved minimum service temperature.
Average absorbed energy, t ≤ 50 mm, L / T, min.	27 J / 20 J	Table 3.2.3. Applies when impact tests are required.
Average absorbed energy, 50 mm < t ≤ 70 mm, L / T, min.	34 J / 24 J	Table 3.2.3.
Average absorbed energy, 70 mm < t ≤ 100 mm, L / T, min.	41 J / 27 J	Table 3.2.3. The Section 2 thickness scope for these plates is t ≤ 100 mm (2.1.1).

The results of all tensile tests and the average energy from each set of three impact tests are to comply with Table 3.2.3. For impact tests, one individual value may be less than the required average provided that it is not less than 70 per cent of this average value (2.4.13). Re-test procedures are in Chapter 1, 4.6. Delivery condition, Table 3.2.2 (Grade D): t ≤ 35 mm, any; 35 mm < t ≤ 100 mm, N, NR or TM. Sections in Grade D may be supplied thicker than 35 mm as-rolled provided satisfactory Charpy results are consistently obtained (note 3). A steelmaker is to supply only those conditions for which it has been approved by LR (2.3.1).

Available Dimensions

Section 2 is primarily intended to apply to steel plates and wide flats not exceeding 100 mm in thickness and to sections and bars not exceeding 50 mm in thickness, in Grades A, B, D and E (2.1.1). For greater thicknesses, variations may be permitted or required for particular applications. Additional approval tests may be required for Grade E plate exceeding 50 mm (2.1.2). For hull-structural plates, strip and wide flats of width ≥ 600 mm, the minus tolerance on thickness is 0.3 mm, irrespective of nominal thickness, and the average thickness is not to be less than the nominal thickness (1.7.3; also 1.7.5 for t below 5 mm). Plus tolerance follows a National or International Standard unless otherwise agreed. Class C of ISO 7452 may be applied in lieu of 1.7.3 (1.7.4). Minus tolerance on bars and sections (except wide flats ≥ 600 mm wide) follows a recognised National or International Standard (1.7.6). Width, length and any stock programme are as agreed for the order; no stock list is implied here.

Main Applications

LR Grade D (LR/D) is used for welded hull and ship structural members specified to this Lloyd’s Register grade. Fitness for a given location, thickness and service is set by the contract design and the attending society.

Equivalent Grades of LR Grade D

Official comparable product pages, where inventoried, are linked below.

Society / standard	Comparable grade	Qualification
ABS	ABS Grade D	Comparison at the same strength and toughness class only.
BV	BV Grade D	Comparison at the same strength and toughness class only.
DNV	DNV Grade D (NV D)	Comparison at the same strength and toughness class only.
GL	GL Grade D	Comparison at the same strength and toughness class only.

Comparison only: not automatic equivalence or substitution. Linked pages state that society’s own requirements, which are not Lloyd’s Register requirements. The July 2022 LR tables on this page are the only LR numerical source used here. No official gangsteel.com product page is inventoried for CCS Grade D or KR Grade D, and none is invented here.

Related Products

Further official Lloyd’s Register hull-steel pages from Gangsteel :

Frequently Asked Questions (FAQ)

What is LR Grade D (LR/D) steel plate?

LR Grade D (LR/D) is a Lloyd’s Register normal-strength hull structural steel in Chapter 3, Section 2 of the July 2022 LR Rules for the Manufacture, Testing and Certification of Materials. The official designation is Grade D. It has a minimum yield of 235 N/mm². Table 3.2.3 sets a −20 °C laboratory impact class.

Does the impact-test temperature define the service limit of LR Grade D (LR/D)?

No. The −20 °C Charpy temperature is a laboratory test condition. Approved service temperature and structural use are set by the ship rules, the design and the attending surveyor.

Can another society’s similarly named grade replace LR Grade D (LR/D) automatically?

No. The Equivalent Grades table is a comparison at the same strength and toughness class, not automatic equivalence or substitution.

Does LR Grade D (LR/D) automatically include through-thickness (Z) properties?

No. Improved through-thickness properties apply only when specified. Chapter 3, Section 8 covers “Z” grade plate, with the supplementary suffix Z25 or Z35 (for example, LR DH36 Z35) as in 1.2.2. They are not implied by the grade name and are not in these official product titles.

What should an enquiry for LR Grade D (LR/D) include?

State LR Grade D (LR/D), the governing rules edition, dimensions, quantity, delivery condition, inspection documents, and any transverse impact or through-thickness testing required. Availability is confirmed for the enquiry; none is implied here.

Contact Gangsteel with your LR Grade D (LR/D) plate specification and project requirements for an order-specific technical and commercial review. Further LR hull-steel pages are listed on the Lloyd’s Register of Shipping shipbuilding steel plates hub and at Gangsteel.