ASTM A573GR70|A573 Grade 70 steel plate supplier

Structural carbon plate where improved notch toughness matters

ASTM A573 Grade 70 belongs to the structural-quality carbon-manganese-silicon plate family. The A573/A573M-25 public abstract describes service at atmospheric temperatures where improved notch toughness is important and requires fine grain practice. Its historical intended use includes ambient-temperature storage-tank construction; that background does not make the grade a general pressure-vessel approval.

For a Gangsteel enquiry, the first decisions are whether the design actually specifies A573 Grade 70 and whether the plate dimensions fall within the specification’s scope. Improved toughness, tensile strength and a particular impact-test acceptance requirement are related purchasing considerations, but they are not interchangeable descriptions of the material.

Keep the structural purpose and thickness boundary together

The 1.5 in. [40 mm] maximum is an official public-Scope limit, not merely a mill’s usual size. Those paired values belong to independent systems, not an exact conversion. A proposal for thicker plate needs a different, appropriately reviewed material basis; it cannot be made an A573 requirement by extrapolating this grade’s properties.

The specification’s toughness intent should be translated into the project’s actual acceptance conditions. If a Charpy examination or another supplementary test is required, identify the test conditions, specimen basis and acceptance criteria in the enquiry. The phrase “improved toughness” does not provide a universal test temperature or energy value.

A573 Grade 70 chemistry with thickness-specific carbon

The following heat-style chemistry summary is a single-compilation public reference from Ferrobend, whose table does not print an ASTM edition year. It is not an official A573/A573M-25 chemistry-table extract. Its phosphorus and sulfur values retain that same source limitation; they are not presented as confirmed official current-edition limits.

Ferrobend’s footnote restates an increase of 0.06 percentage point above the specified manganese maximum for each 0.01 percentage point reduction below the specified carbon maximum, up to 1.60% for Grade 70. That conditional allowance is part of the compilation reference; a separate heat-versus-product split for its ceiling is not established here.

Product-analysis acceptance requires the applicable sampling provisions and tolerances. A heat-style summary does not define those differences, so no product-analysis column is supplied. Request the required analysis records against the ordered edition rather than interpret a missing product value as a zero limit or an instruction to duplicate the heat value.

Mechanical properties need their source, direction and gauge

These are mill restatements cross-checked with a public compilation, not an official mechanical-table extract. SSAB’s Grade 70 datasheet dated 14 June 2019 provides the ksi values and elongations in the transverse direction, with an A6 width-adjustment footnote. Ferrobend supplies the stated SI companions and consistent elongation references. The companions are not claimed as an official SI-table extract.

SSAB’s listed plate offering is 0.188–1.500 in.; it is a mill range, not a Gangsteel supply commitment. Interpret the reference with its source’s product range and the official independent-unit scope limit. On the material report, keep the actual thickness, specimen direction, gauge length and applicable adjustments alongside the result so that comparisons remain meaningful.

Grade 70 does not turn a structural order into a vessel order

The designation ASTM A516 Grade 70 steel plate is associated with a separate pressure-vessel specification. Similar-looking tensile values do not align the material-making requirements, intended service or general requirements. The A573 enquiry remains a structural material requirement under A6, not a vessel requirement under A20.

For the broader distinction between vessel plate and everyday structural carbon plate, see SA-516 vs A36. That comparison explains a material-selection principle; it is not an A573 equivalence chart. A proposed replacement by another structural or vessel grade still requires the appropriate engineering and purchasing approval.

Other A573 grades and a practical order brief

The same-family ASTM A573 Grade 58 steel plate and ASTM A573 Grade 65 steel plate pages are related product routes when those are the designations being considered. Establish the required grade from the component specification before comparing supplier offers. A same-family name does not remove the need to review the selected grade’s requirements.

State the edition, unit system, plate schedule, required delivery condition and documentation scope. If welding is planned, the public Scope presupposes a procedure suitable for the grade and intended use. The responsible fabrication team should establish that procedure; the grade name does not set a welding parameter, preheat value or heat-treatment recipe.

At enquiry stage, separate mandatory material requirements from optional examinations and commercially agreed services. This makes deviations visible before purchase and avoids treating a catalogue description as an agreement to supply every possible condition. Material identification and the agreed test package should remain traceable through the documents delivered with the plate.

Buyer questions about A573 Grade 70 structural plate

Does improved toughness mean a fixed Charpy result?

No fixed temperature or energy follows from that phrase alone. It describes the specification’s material intent, while the required test conditions and acceptance criteria must be established for the project. Where impact testing is required, include the specimen basis, temperature and criteria on the order and review the actual report accordingly.

Can A573 Grade 70 be ordered above 40 mm under this scope?

The A573/A573M-25 public Scope limits plate to 1.5 in. [40 mm], using independent unit systems. An offered thicker product does not create a new A573 property band. Refer a thicker-plate requirement for an appropriate material selection and approval rather than extrapolate the Grade 70 reference beyond the specification limit.

Why are two elongation percentages given?

The published mill reference gives 21% in a 2 in. gauge and 18% in an 8 in. gauge. They are different gauge-based requirements, not interchangeable percentages. SSAB also identifies transverse testing and an A6 width-adjustment footnote. Compare the certificate using the applicable gauge, specimen basis and adjustments for the plate concerned.

Does the chemistry table provide product-analysis limits?

No. It is explicitly a heat-style reference from one compilation without an ASTM year. Product-analysis differences must follow the applicable ordered requirements rather than be inferred by duplicating that table. If product-analysis reporting is required, state it in the enquiry and assess the results on the correct basis.

Is A573 Grade 70 a substitute for A516 Grade 70?

Not automatically. A573 is structural carbon plate with its own scope, while A516 is a vessel-plate specification. Shared strength terminology does not establish the same material requirement or acceptance route. Any alternative needs an appropriate technical review and agreement, not simply a matching Grade 70 label on the quotation.