Grade P under A514: high-yield structural plate, not A517 vessel plate
ASTM A514 Grade P is a quenched-and-tempered alloy steel plate grade for structural applications. The A514/A514M-22 public Scope describes structural-quality plate intended primarily for welded structures and other non-welded structures. Grade P must be ordered under its own designation; the letter P alone does not identify the governing specification.
For Gangsteel enquiries, keep ASTM A514/A514M Grade P, the edition and quenched-and-tempered condition together on the material line. This distinguishes the requested structural product from ASTM A517 Grade P pressure-vessel plate and from other A514 grades. It also avoids treating a broad high-strength-steel description as a complete purchase requirement.
Separate the specification ceiling from a mill’s supply range
The official A514/A514M-22 public Scope covers plate 6 in. [150 mm] and under, but expressly notes that not all grades are available to that maximum. Grade-specific thickness provisions therefore matter; the family-wide ceiling is not proof of every Grade P size or of stock availability.
ArcelorMittal USA’s public A514 and T-1 brochure, available in a 2021 PDF, distinguishes two figures for Grade P: a restated specification maximum of 6 in. and that mill’s own offering maximum of 4 in. Neither figure is a Gangsteel supply commitment. Establish the applicable Grade P thickness provision in the ordered edition and the actual offered size before accepting a quotation.
Inch-pound and SI are separate specification systems. Choose the system used by the project and retain it through dimensions and acceptance requirements. The strength references below use the mill brochure’s inch-pound basis rather than treating rounded conversions as an independently verified SI table.
Grade P chemistry is not a generic A514 recipe
Different A514 grade letters should not share an invented common chemistry. The following values are Grade P heat-analysis references from the ArcelorMittal USA brochure, not a certified extract of the A514/A514M-22 chemistry table. They identify the alloy basis useful for an enquiry without supplying guessed product-analysis tolerances.
| Element | Published heat-analysis value | Basis |
|---|---|---|
| Carbon (C) | 0.12–0.21 | Grade P mill restatement |
| Manganese (Mn) | 0.45–0.70 | Grade P mill restatement |
| Phosphorus (P) | 0.035 max | Mill brochure maximum; ordered edition governs |
| Sulfur (S) | 0.035 max | Mill brochure maximum; ordered edition governs |
| Silicon (Si) | 0.20–0.35 | Grade P mill restatement |
| Chromium (Cr) | 0.85–1.20 | Grade P mill restatement |
| Nickel (Ni) | 1.20–1.50 | Grade P mill restatement |
| Molybdenum (Mo) | 0.45–0.60 | Grade P mill restatement |
| Boron (B) | 0.001–0.005 | Grade P mill restatement |
That mill table does not list vanadium, titanium, zirconium or copper as required Grade P additions. A blank entry is not a zero-content guarantee. Heat analysis and finished-product analysis have different sampling and acceptance bases; obtain the applicable ordered requirements if separate product analysis or additional element reporting is needed.
Thickness-banded strength references for Grade P
| Plate thickness, inch-pound basis | Yield strength, minimum | Tensile strength range |
|---|---|---|
| 2 1/2 in. and under | 100 ksi | 110–130 ksi |
| Over 2 1/2 in. to 6 in., inclusive | 90 ksi | 100–130 ksi |
These are mill-restated values, not an official current-edition mechanical-table extract. The second row is conditional on the Grade P thickness permitted by the ordered specification and the actual supply agreement; it does not extend the mill’s stated offering or establish Gangsteel availability. The strength break shown by this reference is 2 1/2 in.
Specify the applicable elongation requirement, gauge length and test orientation with the order rather than infer them from a strength range. Hardness testing and any permitted substitution of one test for another must follow the applicable requirements. A generic hardness figure is not a replacement for the complete material acceptance basis.
How Grade P differs from related plate choices
| Material | Primary distinction | Decision required |
|---|---|---|
| ASTM A517 Grade P | High-strength quenched-and-tempered alloy plate for fusion-welded boilers and pressure vessels | A separate specification; similar grade letters or chemistry do not establish dual certification or pressure-vessel acceptance for A514 |
| ASTM A537 Class 2 steel plate | Quenched-and-tempered carbon-manganese-silicon pressure-vessel plate | Different material and property basis, not a structural Grade P replacement |
| ASTM A537 Class 1 steel plate | Normalized pressure-vessel plate | A different delivery class and specification |
| ASTM A516 Grade 70 steel plate | Carbon pressure-vessel plate | Select under its own material requirements, not an A514 equivalence assumption |
| ASTM A572 Grade 65 steel plate | Another structural grade under a different specification | A related product topic, not a source of Grade P limits or an automatic substitute |
A514 and A517 may have corresponding grade letters with chemically similar descriptions in mill literature. They still have different specification and delivery bases. If a project needs more than one certification, it must be assessed and documented explicitly; an A514 certificate should not be presented as automatic pressure-vessel approval.
Protect the quenched-and-tempered condition during fabrication
A514’s public Scope presupposes a welding procedure suitable for the grade and intended service. Quenched-and-tempered plate should therefore enter fabrication with the relevant procedure requirements established, not with a general website heat-treatment recipe. Discuss the proposed fabrication route and any additional tests before material acceptance.
The ArcelorMittal brochure warns that post-weld heat treatment can reduce Grade P heat-affected-zone strength and toughness and recommends pretesting. Treat that as material-specific fabrication guidance to evaluate, not as a universal prohibition or an approved WPS. Welding, heat input and any later treatment remain matters for the applicable procedure and responsible engineering review.
Where impact testing or other supplementary requirements are needed, define the conditions and acceptance basis on the enquiry. The Grade P name is not an assigned service-temperature range, a default impact result or a guarantee for every fabricated component.
Buyer questions about A514 Grade P
Is A514 Grade P a pressure-vessel grade because A517 also has Grade P?
No. A514 is the structural plate specification addressed here; A517 is a separate pressure-vessel specification. A matching grade letter or similar chemistry does not make the materials interchangeable or automatically dual-certified. Use the specification called for by the component design and assess any additional certification requirements explicitly.
Can Grade P always be ordered at the A514 family maximum thickness?
Do not assume so. The public Scope’s family ceiling includes a warning that not every grade reaches it. The cited mill brochure separately lists a Grade P specification reference and that mill’s smaller offering range. The ordered edition, grade-specific thickness provisions and actual quotation must all support the requested plate.
Why does the strength table have two thickness bands?
The cited mill reference changes the Grade P yield minimum and tensile range above its stated thickness boundary. Use the correct band for the requested plate and retain the source and unit-system basis. Do not apply a thin-plate value to a thicker order or treat a mill restatement as the full official acceptance table.
Does the chemistry table provide finished-product analysis limits?
No. It is a published Grade P heat-analysis reference. Product analysis uses its own applicable provisions and cannot be completed by copying a heat-analysis row or guessing tolerances. Include any separate product-analysis report and additional element requirements on the enquiry, with the specification edition that governs acceptance.
Can a general quench, temper or preheat schedule be used for Grade P?
Not as a substitute for the required material and fabrication procedures. Grade P is quenched and tempered, but that description is not a shop recipe. Welding and any subsequent heat treatment need a basis suitable for the material and service, including assessment of property changes and any required procedure qualification or pretesting.
Request A514 Grade P on a structural material basis
Send Gangsteel the approved Grade P requirement and plate schedule, including any fabrication-related tests needed for the project.
- ASTM A514/A514M Grade P, ordered edition and unit system
- Dimensions, quantities and quenched-and-tempered delivery condition
- Required analysis, elongation/test basis, impact testing, documents and inspection scope
Identify proposed heat treatment or certification requirements explicitly; do not assume a related grade or specification satisfies them.
Availability, document scope and delivery terms are subject to the quotation for the specific order.