ASTM A514GR.Q|A514 Grade Q quenched and tempered steel plate

Specify Grade Q by its alloy grade, not strength alone

ASTM A514 Grade Q is a quenched-and-tempered alloy structural plate grade. The A514/A514M-22 public Scope addresses structural-quality plate intended primarily for welded structures and other non-welded structures. It is not ASTM A517 pressure-vessel plate, even though A517 also uses a Grade Q designation.

A Gangsteel enquiry should retain Grade Q on the material line together with the ordered edition, unit system and delivery condition. Similar tensile bands across some A514 grades do not make the grade letters optional. The Grade Q chemistry and the material requirements still need to match the design and purchase documents.

Grade Q heat chemistry from the published mill column

The following heat-analysis reference comes from the Grade Q column of ArcelorMittal USA’s public A514 and T-1 brochure, available in a 2021 PDF. It is a mill restatement, not a certified extract of the current ASTM chemistry table. The phosphorus and sulfur figures retain that same brochure basis.

The vanadium range belongs to V, not boron. That mill table does not list boron, titanium, zirconium or copper as required Grade Q additions; an unlisted addition is not a zero-content guarantee. The quoted molybdenum range is Grade Q-specific and should not be replaced with a value taken from another A514 grade.

For finished-product analysis, use the applicable provisions and reporting agreement rather than generate a tolerance column from this heat-analysis table. Heat analysis and product analysis represent different sampling bases. Additional element reporting or tighter chemistry requirements should be identified on the enquiry and assessed for the particular supply.

Strength and elongation: retain the thickness and gauge

SSAB’s published Grade Q page and its datasheet dated 19 April 2017 give the following inch-pound mechanical references. ArcelorMittal’s Grade Q brochure column independently agrees with the yield/tensile split at 2 1/2 in. These are source-specific mill restatements, not an official A514/A514M-22 mechanical-table extract.

The source’s elongation values use a 2 in. gauge length and its stated thickness bands. They should not be compared directly with results at another gauge or assigned to unspecified plate sizes. The AM strength reference uses 2 1/2 in. and under, then over 2 1/2 in. to 6 in.; retain the exact source and the ordered requirements when reviewing a boundary thickness.

SSAB also tabulates 235–293 HBW on its 0.185–0.750 in. row, with a footnote permitting Brinell testing in lieu of tensile testing for plate up to 0.375 in. These are mill-reference testing notes, not a hardness assignment for every Grade Q thickness. Apply the test requirements and any permitted substitution under the ordered acceptance basis.

Interpret the published thickness scope correctly

The official A514/A514M-22 public Scope covers 6 in. [150 mm] and under, with an explicit note that not all grades are available to that maximum. Check the grade-specific thickness provision in the ordered edition and the actual offered dimensions; the family ceiling is not a statement that every size is available.

A mill product sheet’s size range is also not a Gangsteel stock or production commitment. The mechanical table above retains SSAB’s own reference bands so the reader can interpret its test values. For an enquiry, state the exact thickness, width, length and quantity required instead of treating the largest published reference as an assured supply size.

Use inch-pound and SI independently throughout the purchase requirement. The bracketed public-Scope ceiling and the inch-pound mill data should not be mixed as exact conversions or presented as an independently verified SI mechanical table.

Grade Q and related materials: useful distinctions, not equivalents

The Grade P comparison concerns the separately identified grade columns in mill literature, not proof that a sibling product page supplies Grade Q acceptance values. If an alternative material is proposed, obtain the appropriate engineering review and preserve the approved designation in the order and material records.

Fabrication requirements belong with the material enquiry

A514’s public Scope presupposes a welding procedure suitable for the grade and intended service. Quenched-and-tempered condition is not a generic shop recipe for reheating or welding the plate. Identify the intended fabrication route and any proposed later heat treatment so that the responsible team can assess the procedure and required tests.

If impact testing, additional analysis or other supplementary requirements are needed, define their conditions and acceptance basis. Neither a default impact result nor a service-temperature rating follows from the Grade Q name. Agree the required material documents and traceability as part of the order rather than infer them from a general high-strength-steel description.

Buyer questions about A514 Grade Q data

Why does the Grade Q letter matter if another grade has similar strength?

A strength band does not describe the whole material. Grade Q has its own alloy chemistry and applicable requirements. The cited mill literature shows differences from Grade P even where strength-band formats look similar. Keep the specified grade unless an engineering review authorizes an alternative and the order records that decision.

Is the 0.03–0.08% reference vanadium or boron?

It is vanadium in the cited ArcelorMittal Grade Q heat-analysis column. Boron is not listed there as a required Grade Q addition. The table is a mill chemistry reference, not a finished-product analysis or zero-content statement for unlisted elements; use the ordered edition and supply agreement for acceptance.

Which elongation values apply to the published Grade Q reference?

SSAB lists minimum elongation of 16% for 0.185–2.50 in. and 14% for 2.51–6.00 in., both in a 2 in. gauge length. Those are published mill requirements, including the dated datasheet basis, not a certified official ASTM table. Retain the thickness, gauge and source when comparing a report.

Does the A514 family ceiling guarantee the requested Grade Q thickness?

No. The public Scope includes a grade-availability qualification, and published mill ranges describe their own offerings. The exact Grade Q thickness provision and actual quotation need to support the requested size. Give the full plate schedule rather than assume that a specification ceiling or reference data band proves stock availability.

Can an A514 Grade Q certificate also be used as A517 Grade Q certification?

Not merely because the grade letter matches. A517 is a separate pressure-vessel specification with its own requirements and delivery basis. Any dual certification needs explicit assessment and supporting documentation. A structural Grade Q certificate should not be presented as automatic pressure-vessel material acceptance.