ASTM A387 Grade 22 Class 2: compare more than tensile strength
A Grade 22 Class 2 enquiry needs more than a matching tensile range. Its nominal 2.25Cr-1Mo identity distinguishes it from adjacent A387 grades even when selected strength figures coincide. Gangsteel purchasing review starts with the specified Grade 22 material, its required thermal condition and the evidence expected for that order. A similar mechanical result from a different alloy grade does not authorize substitution.
A387/A387M-25 is the current official public edition identified for this page. Official Scope lists Grade 22 at nominal 2.25% chromium and 1.00% molybdenum, within the chromium-molybdenum plate specification for elevated-temperature welded boilers and pressure vessels. Scope provides the grade identity and classification framework. Detailed mechanical values below are separately labelled mill and compilation references, not a claim that the official Tensile Requirements tables were inspected.
Keep the known test basis and the unresolved gauge separate
| Mechanical item | Reference value | Review note |
|---|---|---|
| Tensile strength | 75–100 ksi [515–690 MPa] | Class 2 range |
| Yield strength, minimum | 45 ksi [310 MPa] | Independently checked Grade 22 Class 2 |
| Elongation, minimum; 8 in. [200 mm] gauge | Minimum not established in the references used here | |
| Elongation, minimum; 2 in. [50 mm] gauge | 18% | Identified specimen gauge, not a thickness band |
Grade 22’s mill page and dated 2017 datasheet, checked against public compilations, support the tensile, yield and 2 in. elongation entries. They do not establish an 8 in. minimum for this page. That cell remains blank rather than being completed from Grade 11. A blank is not a zero requirement or a waiver: the purchaser must establish the complete test criteria from the ordered specification and project documents.
Do not reduce the test schedule to “18% elongation” without its gauge. If a report uses another specimen basis, resolve how it is assessed under the applicable requirements before approval. Inch-pound and SI values are independent unit systems, not exact conversions to be combined within one acceptance check. The selected system should remain consistent across the order, dimensions and reported comparison.
This focus matters because the Grade 22 Class 2 tensile and yield reference happens to match Grade 11 Class 2. It does not make the chemical composition, elongation basis or material designation identical. Shared numbers in two columns are useful for comparison, but insufficient evidence that a proposed alternative is suitable for the same design or purchasing requirement.
Separate heat manganese from product manganese
| Element | Heat analysis | Product analysis |
|---|---|---|
| Carbon | 0.05–0.15 | 0.04–0.15 |
| Manganese | 0.30–0.60 | 0.25–0.66 |
| Silicon, maximum | 0.50 | 0.50 |
| Chromium | 2.00–2.50 | 1.88–2.62 |
| Molybdenum | 0.90–1.10 | 0.85–1.15 |
| Phosphorus, max | 0.025 | 0.025 |
| Sulfur, max | 0.025 | 0.025 |
| Ni, V, Nb, B, N, Al, W |
The chemistry splits come from independently checked stockist and dated September 2026 compilations. Official Table 1 and its footnotes were not inspected. Treat the table as a public reference and confirm every requirement, including the compilation phosphorus and sulfur maxima, in the ordered edition. No limit is invented for the blank element row, and no uninspected official carbon footnote is restated.
Manganese illustrates why the two analysis columns cannot be merged: 0.30–0.60% is the heat band, while 0.25–0.66% is the product band in these references. An enquiry attachment should say which it is using. Silicon needs a different reading: 0.50% is a maximum in both columns, not a target value and not the midpoint of an implied range. Lower and upper limits for chromium and molybdenum must also remain identified as ranges.
When comparing documentation, retain the reported analysis type and heat identification beside the numbers. If an offer provides a product-style range without a heat column, ask for the intended compliance basis rather than silently treating it as heat analysis. Any purchaser-requested chemistry restriction should be distinguished from the standard reference so that an additional condition does not become an undocumented assumption.
Specify the condition represented by the results
Official ASTM abstract describes killed and thermally treated steel. It does not provide the detailed treatment route on the public Scope page. Labelled compilations describe usual Class 2 delivery as normalized and tempered, or accelerated cooling plus temper, and exclude annealed plate from the Class 2 tensile basis. Confirm this compilation restatement against the ordered edition and identify the required delivery condition in the purchase documents.
No treatment temperatures, welding parameters or service-temperature limit are supplied here. Elevated-temperature application in Scope is not a guaranteed operating rating for an individual vessel design. The purchaser’s engineering requirements must establish the relevant service and fabrication criteria. Ask separately for any required impact testing, examinations or treatment records, with their acceptance basis; none is promised as a default package.
| Checkpoint | Information to carry forward | Question to close |
|---|---|---|
| Material designation | A387 or A387M, Grade 22, Class 2, edition | Is the quoted material exactly the ordered grade and class? |
| Size and units | Dimensions and quantity for each line; governing unit system | Are document and size references unambiguous? |
| Thermal condition | Required treated state and relevant purchaser conditions | Do the results represent the agreed material condition? |
| Acceptance criteria | Complete tests, specimen bases and additional requirements | Has the unresolved gauge or missing evidence been addressed? |
| Identification and documents | Plate/heat linkage and required certificate form | Can the receiving review follow each purchase line? |
Official Scope limits maximum thickness only by the composition’s capacity to meet specified mechanical properties. It is not a numerical cap and does not establish a mill’s size capability. Review the requested thickness with condition and acceptance details, not as a stand-alone marketing dimension. Grade and class should remain explicit when an offer is revised or a document package is resubmitted.
Related family topics are Grade 11 Class 2 and Grade 12 Class 2. Those navigation links are not technical sources or equivalence statements. ASTM and ASME material acceptance remain separate: an A387 certificate alone does not establish SA-387 acceptance, and the reverse is not automatic. Specify any dual-certification requirement for review, without assuming a current Code year.
Buyer questions
Is Grade 22 simply another name for Grade 11 at the same strength?
No. Official Scope gives Grade 22 nominal 2.25Cr-1.00Mo. A shared public-reference tensile and yield level does not erase the different alloy identity or establish interchangeability. Retain the exact drawing designation when requesting an offer.
What does the blank 8 in. elongation cell mean?
The allowed Grade 22 sources did not independently establish that minimum. It is intentionally not filled from a neighbouring grade. Determine the complete acceptance requirement from the ordered edition; blank here does not mean zero or permission to omit a required test.
How should the silicon and manganese entries be read?
Silicon is 0.50% maximum on both analyses in the labelled compilations. Manganese is heat 0.30–0.60% and product 0.25–0.66%. Treating silicon as a target or labelling the heat manganese band as product would misstate the reference.
Does the official public page require one detailed heat-treatment recipe?
It states killed and thermally treated in the abstract. The usual normalized-and-tempered or accelerated-cooling-plus-temper description here is a compilation restatement, not the paid official clause. Agree the route using the ordered edition; no numerical treatment temperatures are prescribed.
Which requirements should accompany a Grade 22 quotation request?
Include A387 or A387M, Grade 22, Class 2, edition, dimensions, units, delivery condition, tests and certificate form. Identify any required dual certification explicitly. Similar designations or mechanical results do not automatically satisfy a separate acceptance route.
Enquire with the complete Grade 22 requirement
Provide the size schedule and governing specification, then attach the thermal-condition, test and document requirements. Flag unresolved specimen or acceptance details so they can be closed during quotation review, not assumed at receiving inspection.