ASTM A564/A564M specifies hot-finished and cold-finished age-hardening stainless steel bars and shapes. For buyers of 17-4PH and 15-5PH bar, a usable enquiry combines the standard, UNS grade, dimensions and heat-treatment condition. “ASTM A564 stainless steel” alone leaves important purchasing details open.
This page explains the purchasing requirements and common grade choices. For a material overview, see 17-4PH stainless steel or 15-5PH stainless steel.
1. Standard Scope & Designation
| Item |
Scope / ordering interpretation |
| Edition checked |
ASTM A564/A564M-25; specify the edition required by your contract. |
| Forms |
Rounds, squares, hexagons and shapes, including angles, tees and channels. |
| Production routes |
Hot rolling, extrusion or forging; billets and bars for reforging are also addressed. |
| Units |
A564 and A564M use separate inch-pound and SI requirements. Select one system; do not mix acceptance values. |
| Product boundary |
Finished age-hardening stainless steel forgings: consult A705/A705M. Forging stock: also check A314. |
The ASTM scope describes general use up to 600°F [315°C], with exceptions for Type 632 and UNS S46910. This is not an allowable-stress table or an approval for a specific pressure component.
2. Stainless Steel Grades — Common Purchasing Choices
| Commercial designation |
Type / UNS |
Buying focus |
| 17-4PH |
Type 630 / S17400 |
A widely used choice for machined high-strength stainless components. |
| 15-5PH |
XM-12 / S15500 |
Consider when transverse properties and toughness are important; review the required material specification. |
| Other age-hardening grades |
Check the selected edition |
Confirm grade coverage and permitted conditions before issuing an order; this is a common-grade guide, not a complete grade list. |
Types 631 and 632 require particular care for large sections because of ductility limitations identified in the ASTM scope. Do not assume every PH grade is suitable for every bar diameter.
3. Chemical Composition — 17-4PH & 15-5PH Reference
The table below summarizes selected composition values from producer literature, in weight percent. It is a grade-identification reference, not a reproduction of the complete A564-25 chemistry table. Contract acceptance must use the specified edition, including all elements and applicable analysis tolerances.
| Element |
17-4PH reference |
15-5PH reference |
| Chromium (Cr) |
15.00–17.50% |
14.00–15.50% |
| Nickel (Ni) |
3.00–5.00% |
3.50–5.50% |
| Copper (Cu) |
3.00–5.00% |
2.50–4.50% |
| Carbon (C), max. |
0.07% |
0.07% |
| Manganese (Mn), max. |
1.00% |
1.00% |
| Silicon (Si), max. |
1.00% |
1.00% |
Request a heat-specific chemical analysis. A commercial name or a handheld alloy-identification result should not replace the mill test report.
4. Mechanical Properties — Read the Condition and Size Together
Strength values are meaningful only when the grade, section size, test orientation and heat-treatment condition are identified. A result from an aged test specimen also needs to be distinguished from the delivery condition of the bar.
| 17-4PH condition |
Tensile strength, min. |
0.2% yield strength, min. |
Elongation, min. |
| H900 — section up to 75 mm (3 in.) |
1310 MPa (190 ksi) |
1170 MPa (170 ksi) |
10% |
| H1025 — section up to 200 mm (8 in.) |
1070 MPa (155 ksi) |
1000 MPa (145 ksi) |
12% |
| H1150 — section up to 200 mm (8 in.) |
930 MPa (135 ksi) |
725 MPa (105 ksi) |
16% |
Reference basis: Selected bar values from the ARMCO 17-4PH producer datasheet, Table 3; elongation is reported in 4D. These values are not a complete A564-25 acceptance table and do not apply automatically to 15-5PH, all section sizes or transverse specimens. Confirm hardness, reduction of area, impact requirements and sampling with the contract specification. SI and inch-pound acceptance values must be checked independently.
5. Heat Treatment & Delivery Condition
| Condition |
What to clarify in the enquiry |
| Condition A |
Solution-treated supply; identify whether the buyer or supplier will perform subsequent aging. |
| H900 |
High-strength aging condition; check the required toughness and environmental suitability. |
| H1025 / H1075 / H1100 |
Name the exact condition. Similar designations do not make the mechanical requirements identical. |
| H1150 |
State the required properties and test condition; do not substitute a double-aging cycle without agreement. |
| H1150D / H1150M |
Specify the exact multi-step treatment and governing specification; do not shorten the designation to H1150. |
Heat-treatment designations are grade-specific. Ask the supplier to confirm the permitted delivery state, required cycle, and acceptance testing for the selected grade. For parts machined before aging, agree machining allowances and the point at which final dimensions will be verified.
6. Testing & Inspection Requirements
| Inspection item |
Purchase-order detail |
| Chemical analysis |
Heat number, grade and required analysis report. |
| Mechanical testing |
Grade, condition, section size, specimen orientation and applicable tensile, hardness and impact requirements. |
| Surface and dimensions |
Finish, straightness, dimensional tolerance and permitted surface condition. |
| Traceability |
Marking and heat identification maintained after cutting. |
| Additional examination |
If needed, specify ultrasonic testing or PMI method, extent, acceptance criteria and reporting. |
| Documentation |
Specify the required inspection document, such as EN 10204 3.1, rather than assuming it is included. |
Separate base-standard requirements from additional customer requirements. A request for “UT tested” needs an examination standard and acceptance criteria; a request for “certified material” needs an identified certificate type.
7. Dimensions, Finish & Tolerances
For round bar, state diameter and length. For square or hexagonal bar, state the appropriate section dimension; for shapes, supply a drawing or section designation. Add the delivery finish, cutting tolerance, straightness and any machining allowance. Confirm applicable general requirements and tolerance provisions, including ASTM A484/A484M where invoked by the governing specification.
| Order field |
Example wording |
| Section |
Round bar, diameter 50 mm |
| Length |
Cut length 3000 mm; length tolerance to be agreed |
| Finish |
Peeled or ground; specify the required dimensional tolerance |
| Quantity |
Number of pieces and total quantity |
| Special dimensions |
Drawing revision and critical finished dimensions, if applicable |
8. Industries & Applications
Typical engineering uses for PH stainless bar include shafts, valve stems, pump components, fastener blanks and machined structural parts. These examples describe possible applications, not approvals granted by A564. The component designer must establish fatigue, toughness, corrosion and temperature requirements before choosing a grade and condition.
For aerospace parts, name the required AMS specification and any melting or cleanliness requirement. For sour-service components, specify the applicable NACE/ISO requirements and service conditions; an A564 certificate alone does not establish that qualification.
9. Grade & Condition Selection Guide
| Buyer priority |
What to review |
| High static strength |
Required yield strength, section size and heat-treatment condition. |
| Transverse toughness |
Compare qualified 17-4PH and 15-5PH data with the same orientation and test conditions. |
| Machining before final aging |
Delivery in Condition A, responsibility for aging and final dimensional checks. |
| Corrosive service |
Actual medium, temperature, stress state and the selected condition. |
| Large bar section |
Through-section properties, sampling location and any additional inspection. |
| Replacement material |
Drawing requirements and customer approval; commercial grade names alone do not establish equivalence. |
10. Related Standards & ASTM A564 vs B564
| Standard |
Relationship / purchasing boundary |
| ASTM A564/A564M |
Age-hardening stainless steel bars and shapes. |
| ASTM A705/A705M |
Age-hardening stainless steel forgings. |
| ASTM A314 |
Stainless steel billets and bars for forging. |
| ASTM A484/A484M |
General requirements relevant to stainless bars and shapes when invoked. |
| ASTM B564 |
Nickel alloy forgings; not a substitute for A564 stainless bar. |
| AMS / ASME requirements |
Confirm the exact material specification, adopted edition and component-code requirements if the project calls for them. |
11. How to Order — Required Information
Send HT PIPE the grade, standard edition, dimensions, quantity, delivery condition and required documentation. Include drawing and inspection requirements at the enquiry stage so the quotation addresses the actual acceptance criteria.
Example RFQ: ASTM A564/A564M-25, metric requirements; Type 630 / UNS S17400 (17-4PH); H1025 delivery condition; round bar Ø50 mm × 3000 mm; 20 pieces; finish and tolerances to be agreed; EN 10204 3.1 inspection certificate requested. Confirm the applicable mechanical acceptance values and report the test condition. Add UT requirements only with an agreed examination standard and acceptance criteria.
12. Frequently Asked Questions
Q: What is ASTM A564?
ASTM A564/A564M is a material specification for age-hardening stainless steel bars and shapes. A purchase order should identify the steel grade, product form, size and delivery condition.
Q: Is ASTM A564 the same as 17-4PH?
No. ASTM A564 is a product specification; 17-4PH is a steel grade, identified as Type 630 and UNS S17400. Specify both the standard and grade, together with the required heat-treatment condition.
Q: Can 15-5PH bars be ordered to ASTM A564?
Yes. Identify 15-5PH as XM-12, UNS S15500, and state the required delivery condition and mechanical acceptance criteria. Confirm the applicable edition and any additional customer specification with the supplier.
Q: What is the difference between Condition A and H900?
Condition A identifies solution-treated material; H900 identifies an aging condition. State whether aging is required before delivery or will be performed after machining, and identify the condition in which acceptance tests must be performed.
Q: What is the difference between ASTM A564 and ASTM B564?
A564 concerns age-hardening stainless steel bars and shapes. B564 concerns nickel alloy forgings. Their similar numbering does not make them interchangeable.
Q: Does ASTM A564 cover finished stainless steel forgings?
For finished age-hardening stainless steel forgings, check ASTM A705/A705M. A bar produced by forging and a finished shaped forging are different purchasing categories.
Q: Does an ASTM A564 certificate automatically establish aerospace or sour-service compliance?
No. Add the required aerospace or sour-service specification to the order and verify its material, processing, heat-treatment, hardness, testing and service restrictions separately.
Request a Quote — ASTM A564 Stainless Steel Bars
Send your 17-4PH or 15-5PH bar enquiry to HT PIPE. Include the UNS grade, size, delivery condition, quantity and inspection requirements. Ask us to confirm supply availability, processing options and documentation for your order.
info@htpipe.com | +86-371-60953359
