What PH13-8Mo is
PH13-8Mo is the common shop name for the alloy specified generically as UNS S13800, ASTM A564 Type XM-13 for bars and shapes, ASTM A705 Type XM-13 for forgings, AMS 5629 for bars, wire, forgings, rings and extrusions, AMS 5864 for flat products and EN 1.4534 in Europe. The composition runs 12.25 to 13.25 percent chromium, 7.50 to 8.50 percent nickel, 2.00 to 2.50 percent molybdenum and 0.90 to 1.35 percent aluminium, with carbon held to 0.05 percent maximum and manganese and silicon to 0.10 percent each.
It is solution treated at 927 °C and cooled below 16 °C so the structure transforms fully to martensite, then aged for four hours somewhere between 510 and 621 °C. Strength is set by the aging temperature: the specified minimum tensile strength runs from 1,517 MPa in H950 down to 931 MPa in H1150. Density is 7.76 g/cm³ and the alloy is ferromagnetic in every condition.
The reason it is specified over cheaper precipitation-hardening grades is not the strength on its own. Because the carbon, manganese, silicon and sulfur limits are so tight and the steel is vacuum melted, transverse and short-transverse ductility stay close to the longitudinal values in thick sections. AMS 5864 specifies short-transverse reduction of area as a separate requirement, from 35 percent in H950 up to 50 percent in H1150, which few stainless specifications do.
Who supplies the forgings on this page
Jiangyin Jiangnan Metal Co., Ltd. has been melting and forging steel at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China since 1997. Standard grades run through the electric arc furnace, the ladle furnace and vacuum oxygen decarburisation. Clean grades such as UNS S13800 take the vacuum induction and vacuum arc remelting route, with 3 t and 6 t protective-atmosphere electroslag furnaces also on site. From there the steel goes to the 6,300 t, 4,000 t and 2,000 t presses, the 6 m, 3 m and 1 m ring mills, 14 heat-treatment furnaces and the machine shop without leaving the plant, so one heat number follows the part to the certificate. 460 staff, including 9 senior and 32 intermediate engineers. Approvals from CCS, BV, DNV, LR and NK.
| UNS number | S13800 |
|---|---|
| Alloy type | Martensitic precipitation-hardening stainless steel, strengthened by nickel-aluminium intermetallics rather than carbides |
| Nominal composition | 12.7 Cr, 8 Ni, 2.2 Mo, 1 Al, 0.05 C maximum |
| Density | 7.72 to 7.76 g/cm³ (0.279 to 0.280 lb/in³) |
| Melting range | 1404 to 1471 °C (2560 to 2680 °F) |
| Dynamic modulus | 200 GPa at 21 °C, 194 GPa at 100 °C |
| Strength range | 931 MPa minimum in H1150 to 1,517 MPa minimum in H950; about 1,620 MPa typical in RH950 |
| Hardness range | 30 HRC minimum in H1150 to 45 HRC minimum in H950; about 48 HRC typical in RH950 |
| Solution treatment | 927 °C plus or minus 8 °C, cool below 16 °C |
| Aging | 510 to 621 °C, four hours, air cool |
| Forging range | 1177 to 1204 °C; finish above 954 °C |
| Magnetic | Yes, in all conditions |
| Corrosion resistance | Salt-fog rusting resistance in H950 similar to Type 304; general corrosion resistance approaching Type 304 |
| Lead time | 20 to 60 days, the upper end for double-melt material |
Property data: Rolled Alloys Data Sheet 13-8 Stainless, Bulletin 1022USe; High Temp Metals PH 13-8 Mo technical data. Capability, lead time and approvals: Jiangyin Jiangnan Metal production records.
Two figures circulating for this grade are wrong, and the earlier version of this page repeated them. ASTM B564 is quoted on a number of supplier pages for PH13-8Mo, but B564 covers nickel-alloy forgings and has nothing to do with UNS S13800. The correct forging specification is ASTM A705 Type XM-13, or AMS 5629. The conditions H900, H925 and H1075 are also often listed for this grade; they belong to 17-4PH. PH13-8Mo is aged at 950, 1000, 1025, 1050, 1100 or 1150 °F, plus the refrigerated RH950 cycle and the double-aged H1150M cycle. Both points were corrected here in October 2026.
Forged shapes we produce
Three routes: open-die forging for shafts, blocks, discs and tube sheets; seamless ring rolling for rings from 50 to 6,000 mm outside diameter; and upset-and-punch forging for short, large-section discs and hubs below the ring-mill range. Everything is worked from a single piece of steel melted in our own furnaces.
Working envelope
- Single-piece weight to 30,000 kg on the 6,300 t press
- Rolled ring outside diameter to 6,000 mm; from 50 mm by upset and punch
- Turned shafts to 14,000 mm, with 15 m well furnaces for vertical quenching
- Machined discs to 5,000 mm swing
- Deep-hole bored cylinders to 1,600 by 10,000 mm
For UNS S13800 the clean-melt ingot governs rather than the press. The 3 t vacuum induction and 6 t vacuum arc remelting furnaces set the realistic ceiling for double-melt material, so confirm the melt route before committing to a size.
Which specification to cite
ASTM A705 Type XM-13 for an industrial forging order, AMS 5629 for aerospace bars, forgings, rings and extrusions, EN 1.4534 for European projects. ASTM A564 Type XM-13 covers bars and shapes and AMS 5864 covers sheet, strip and plate. PH 13-8 Mo itself is a trademark, not a specification.
| Origin | Designation | Scope |
|---|---|---|
| United States, brand | PH 13-8 Mo | Registered trademark of Cleveland-Cliffs Inc., formerly AK Steel and Armco. We do not sell under this name and supply the generic equivalents below. |
| United States, UNS | UNS S13800 | Unified Numbering System designation |
| ASTM, bars and shapes | ASTM A564 Type XM-13 | Hot-rolled and cold-finished age-hardening bars, rods and shapes |
| ASTM, forgings | ASTM A705 Type XM-13 | The specification to cite on a forging order |
| ASTM, flat products | ASTM A693 Grade XM-13 | Plate, sheet and strip |
| SAE, bars and forgings | AMS 5629 | Bars, wire, forgings, rings and extrusions, the usual aerospace specification for forged material |
| SAE, flat products | AMS 5864 | Sheet, strip and plate, and the source of the minimum property table in section 06 |
| Europe | EN 1.4534, X3CrNiMoAl13-8-2 | European material number and name for the same chemistry |
| Shop-floor names | 13-8Mo, 13-8 PH, 13/8 Mo, 13/8PH | Informal names on legacy drawings, all meaning UNS S13800 |
| Does not apply | ASTM B564 | A nickel-alloy forging specification, frequently cited for this grade in error |
Compiled from SSA Corp AMS 5629 and UNS S13800 listings, California Metal and Supply ASTM A564 and A705 XM-13 listings, product-form comparison of AMS 5629 against AMS 5864, and EN 10088-3 for 1.4534.
Chemical composition
Chromium 12.25 to 13.25, nickel 7.50 to 8.50, molybdenum 2.00 to 2.50, aluminium 0.90 to 1.35, carbon 0.05 maximum, manganese 0.10 maximum, silicon 0.10 maximum, phosphorus 0.01 maximum, sulfur 0.008 maximum, nitrogen 0.01 maximum, balance iron, all in weight percent.
| Element | Minimum | Maximum | Function |
|---|---|---|---|
| Carbon | – | 0.05 | Held low because strengthening comes from intermetallic precipitates, not carbides |
| Manganese | – | 0.10 | One tenth of the 17-4PH limit, to suppress manganese sulfide inclusions |
| Silicon | – | 0.10 | Held low for cleanliness and transverse ductility |
| Phosphorus | – | 0.01 | Residual, embrittles grain boundaries |
| Sulfur | – | 0.008 | Residual, the tightest limit among the common precipitation-hardening grades |
| Nitrogen | – | 0.01 | Controlled, so reducing furnace atmospheres have to be avoided during heat treatment |
| Chromium | 12.25 | 13.25 | Corrosion resistance and martensite stability |
| Nickel | 7.50 | 8.50 | Toughness, and partner to aluminium in the strengthening phase |
| Molybdenum | 2.00 | 2.50 | Pitting resistance and solid-solution strengthening |
| Aluminium | 0.90 | 1.35 | The precipitation-hardening element, forming nanoscale nickel-aluminium precipitates on aging |
| Iron | Balance | Matrix | |
Rolled Alloys Data Sheet 13-8 Stainless and High Temp Metals PH 13-8 Mo technical data agree on all limits shown.
No part of this table can be reached by air melting. Carbon at 0.05 percent with manganese and silicon at 0.10 percent and sulfur at 0.008 percent needs vacuum induction melting followed by vacuum arc remelting, which is why most forging shops buy UNS S13800 billet rather than make it. We run both furnaces, so the chemistry on the certificate is our own heat.
Heat-treatment conditions
Solution treat at 927 °C and cool below 16 °C for Condition A, then age four hours at the chosen temperature and air cool. RH950 adds a hold at minus 73 °C before aging at 510 °C, which clears retained austenite and gives the highest strength. H1150M is a two-stage cycle at 760 then 621 °C for the best toughness and machinability.
| Condition | Cycle | Notes |
|---|---|---|
| A | 927 °C plus or minus 8 °C, typically one hour at temperature, cool below 16 °C | Sections under roughly 230 cm² may be liquid quenched, larger sections air cooled. The structure has to transform fully to martensite or the alloy will not age properly. |
| RH950 | Cool Condition A material to minus 73 °C for two hours or more within 24 hours of solution treatment, warm in air, age 510 °C plus or minus 6 °C for four hours, air cool | Highest strength available. The cold hold eliminates small amounts of retained austenite, which is what optimises the aging response. |
| H950 | 510 °C, four hours, air cool | Highest-strength single-step condition |
| H1000 | 538 °C, four hours, air cool | Lowest aging temperature recommended where stress-corrosion cracking governs |
| H1025 | 552 °C, four hours, air cool | Intermediate strength |
| H1050 | 566 °C, four hours, air cool | Common balance of strength and toughness |
| H1100 | 593 °C, four hours, air cool | Higher toughness |
| H1150 | 621 °C, four hours, air cool | Highest-toughness single-step condition. Overaged, so it will not respond to further aging. |
| H1150M | 760 °C, two hours, air cool, then 621 °C, four hours, air cool | Highest impact energy and the best machinability of the aged conditions. Also overaged, so further aging needs re-solution treatment at 927 °C. |
High Temp Metals PH 13-8 Mo technical data for the cycle definitions and the RH950 refrigeration requirement. Rolled Alloys gives the solution treatment as 913 to 941 °C for 15 to 30 minutes with air cooling or an oil quench below 16 °C, and the aging tolerance as plus or minus 6 °C for four hours plus or minus 15 minutes.
Three points to settle before the order is placed. H1150 and H1150M are terminal conditions, so material supplied in either one for easier machining has to be re-solution treated at 927 °C before it can be aged again. Hardness alone cannot separate H1150 from Condition A, because the H1150 hardness range falls inside the solution-treated range, so the certificate is the evidence rather than a hardness tester. Aging produces a small contraction that increases with aging temperature, so tight-tolerance features are better finish-machined after aging.
Mechanical properties
Specified minima run 1,517 and 1,414 MPa tensile and yield in H950 at 45 HRC, down to 931 and 621 MPa in H1150 at 30 HRC. Short-transverse reduction of area is specified separately, from 35 percent in H950 to 50 percent in H1150.
Specified minima
| Property | H950 | H1000 | H1025 | H1050 | H1100 | H1150 |
|---|---|---|---|---|---|---|
| Yield strength, 0.2 percent, ksi | 205 | 190 | 175 | 165 | 135 | 90 |
| Yield strength, 0.2 percent, MPa | 1414 | 1310 | 1207 | 1138 | 931 | 621 |
| Tensile strength, ksi | 220 | 205 | 185 | 175 | 150 | 135 |
| Tensile strength, MPa | 1517 | 1414 | 1276 | 1207 | 1034 | 931 |
| Elongation in 50 mm, percent | 10 | 10 | 11 | 12 | 14 | 14 |
| Reduction of area, longitudinal, percent | 45 | 50 | 50 | 50 | 50 | 50 |
| Reduction of area, transverse, percent | 45 | 50 | 50 | 50 | 50 | 50 |
| Reduction of area, short transverse, percent | 35 | 40 | 45 | 45 | 50 | 50 |
| Hardness, minimum | 45 HRC | 43 HRC | – | 40 HRC | 34 HRC | 30 HRC |
Rolled Alloys Data Sheet 13-8 Stainless, Bulletin 1022USe, tabulating minimum mechanical properties to AMS 5864. Metric values converted at 1 ksi equals 6.895 MPa and rounded. Confirm against the edition of AMS 5629, ASTM A705 or AMS 5864 named on the purchase order.
Typical values, including RH950 and H1150M
| Condition | Yield, MPa | Tensile, MPa | Elongation, percent | Reduction of area, percent | Hardness, HRC | Charpy V, J |
|---|---|---|---|---|---|---|
| RH950 | 1482 | 1620 | 12 | 45 | 48 | 27 |
| H950 | 1448 | 1551 | 12 | 50 | 47 | 27 |
| H1000 | 1413 | 1482 | 13 | 55 | 45 | 41 |
| H1050 | 1241 | 1310 | 15 | 55 | 43 | 68 |
| H1100 | 1034 | 1103 | 18 | 60 | 35 | 81 |
| H1150 | 724 | 1000 | 20 | 63 | 33 | 103 |
| H1150M | 586 | 896 | 22 | 70 | 32 | 163 |
High Temp Metals PH 13-8 Mo technical data, typical longitudinal room-temperature properties. Typical values, not specification minima; design to Table 3. Tensile modulus in H1000 is given as 195 GPa.
Transverse values in the same source sit close to the longitudinal ones. In H1000 the transverse yield strength matches the longitudinal figure and reduction of area is 50 percent against 55 percent. That near-isotropy is the commercial argument for the grade. A conventional high-strength stainless can lose a large part of its transverse ductility in a heavy forging, whereas UNS S13800 barely moves, which is why it appears on drawings for thick landing-gear sections, trunnions, actuator cylinders and critical valve parts.
Torsional properties
| Condition | Yield at 0.2 percent shear strain | Yield at 0.2 percent normal strain | Modulus of rupture | Modulus of rigidity |
|---|---|---|---|---|
| H950 | 945 MPa | 1020 MPa | 1269 MPa | 76.5 GPa |
| H1000 | 924 MPa | 986 MPa | 1186 MPa | 75.2 GPa |
High Temp Metals PH 13-8 Mo technical data, published as 137, 148, 184 and 11.1 by 10³ ksi for H950 and 134, 143, 172 and 10.9 by 10³ ksi for H1000. Useful for shaft and valve-stem torque checks.
Physical properties
| Property | Value | Condition or temperature |
|---|---|---|
| Density | 7.72 to 7.76 g/cm³, 0.279 to 0.280 lb/in³ | Rolled Alloys publishes 0.279, High Temp Metals 0.280 |
| Melting range | 1404 to 1471 °C, 2560 to 2680 °F | – |
| Dynamic modulus of elasticity | 200 GPa, 29.0 by 10⁶ psi | 21 °C |
| Dynamic modulus of elasticity | 194 GPa, 28.1 by 10⁶ psi | 100 °C |
| Tensile modulus | 195 GPa | H1000 |
| Modulus of rigidity | 76.5 GPa in H950, 75.2 GPa in H1000 | Room temperature |
| Thermal conductivity | 8.6 Btu ft per ft² h °F, about 14.9 W per m K | 21 °C |
| Thermal conductivity | 10.4 Btu ft per ft² h °F, about 18.0 W per m K | 300 °C |
| Coefficient of thermal expansion | 7.2 by 10⁻⁶ in per in °F at 100 °C, rising to 7.8 at 300 °C, as published | Mean from 21 °C |
| Electrical resistivity | 613 ohm circular mil per ft, about 1.02 microhm m | Condition A |
| Magnetic response | Ferromagnetic in all conditions | – |
Rolled Alloys Data Sheet 13-8 Stainless for melting range, dynamic modulus, conductivity and expansion; High Temp Metals PH 13-8 Mo technical data for density, resistivity and tensile modulus. Expansion is reproduced in the published imperial form; confirm against the governing specification before using it in a design calculation.
Corrosion behaviour
Rusting resistance in salt fog in the H950 condition is similar to Type 304, and general corrosion resistance in oxidising and reducing acids and in atmospheric exposure approaches Type 304. Resistance is highest in the fully hardened condition and falls slightly as the aging temperature rises. Where stress-corrosion cracking governs, age at 538 °C or above.
Marine-atmosphere testing is where the grade earns its place. In bent-beam exposure at Kure Beach, specimens aged at 538 and 566 °C survived long-term exposure at stress levels up to the yield strength without failure, while specimens aged at the lowest temperature produced scattered failures. Welded material behaves the same way provided it is re-solution treated before aging. Specimens that were welded and then aged directly failed early; specimens that were solution treated again after welding and then aged showed no failures.
That contrast is the most useful practical point here. If a PH13-8Mo part is welded and will carry sustained stress in a chloride-bearing environment, the welded assembly has to go back through 927 °C solution treatment before aging. Aging straight after welding is the route to a field failure.
Elevated temperature. Oxidation resistance is good to roughly 593 °C. Long exposure between about 288 and 482 °C can reduce toughness in precipitation-hardenable stainless steels, so that band is worth avoiding in service. Short excursions are acceptable as long as the peak stays well below the aging temperature. For best corrosion resistance the surfaces must be free of scale and embedded iron, and finished parts should be passivated.
Sour service is not a property of the grade. NACE MR0175 and ISO 15156-3 list precipitation-hardening stainless steels with named heat-treatment conditions, hardness ceilings and limits on hydrogen sulfide partial pressure, chloride concentration, pH and temperature. Acceptance is tied to the condition and the environment, not to the grade, and the editions change. Send the hydrogen sulfide partial pressure, chloride level, pH and maximum temperature with the enquiry so the requirement can be reviewed before the order is accepted. For sour-service work the grade we supply most often is 17-4PH in the H1150-M condition.
Forging, machining and welding
Hot working
| Heating | Heat uniformly to 1177 to 1204 °C and soak one hour at temperature before forging |
|---|---|
| Finishing temperature | Do not forge below 954 °C |
| Cooling after forging | Air cool to about 16 °C before further processing, for grain size and properties |
| Mandatory step | Forgings have to be solution treated before aging. Hot-worked material that skips solution treatment will not harden properly. |
| Cutting | Cold saw bars and forging billets. Abrasive-wheel cutting can start small surface cracks, particularly in annealed stock. |
| Descaling | Acid clean or grit blast after forging and annealing. After acid cleaning, bake one to three hours at 150 to 177 °C to release hydrogen. |
High Temp Metals PH 13-8 Mo technical data, workability section. The 1177 °C soak before forging is also published by California Metal and Supply.
Machining
In Condition A the alloy gives good tool life and finish, but at surface speeds 20 to 30 percent below Custom 630 and 20 to 30 percent below Types 302 and 304. Machinability in the aged conditions improves as the aging temperature rises, and H1150M gives the best machinability of the aged conditions, with the caveat that higher properties can then only be developed by re-solution treating and re-aging. Published high-speed-steel starting points for solution-treated material are about 18 m/min for turning, cut-off and forming, 15 m/min for drilling, 27 m/min for end and peripheral milling at 1.3 mm depth of cut, and 3 m/min for broaching. Carbide tooling allows surface speeds two to three times higher and feeds 50 to 100 percent higher.
Correction to the earlier text on this page. It said the grade machines much like Types 302, 303, 410, 420, 430 and 430F. That understates it. The published guidance is 20 to 30 percent slower than 302 and 304 and 20 to 30 percent slower than 17-4PH, and in the high-strength aged conditions turning, drilling and threading are demanding. Rough in Condition A or H1150M, then age.
Welding
The alloy can be welded by inert-gas shielded or resistance processes. Matching PH 13-8 filler gives weld properties close to the base metal, and where high weld strength is not needed an austenitic filler such as E or ER308L can be considered. Preheat is usually unnecessary. Joint design should avoid sharp corners, threads and partial-penetration welds. Welding in the solution-annealed condition is normal practice and the part can then be aged. Welding in the overaged H1150 condition is sometimes chosen where welding stresses are high, but material welded in that condition has to be solution treated before aging, as the corrosion data in section 08 shows.
Applications
Published application lists for UNS S13800 centre on valve parts and fittings, cold-headed and machined fasteners, shafts, pins, aircraft components and landing-gear structure, nuclear reactor components, injection-moulding tooling, and petrochemical equipment where resistance to stress-corrosion cracking matters. The selection rule is high strength, toughness and corrosion resistance together with little directionality in properties.
Aerospace and landing gear
Struts, trunnions, axles and actuator cylinders, airframe fittings and machined fasteners. The heavy-section transverse ductility is the reason, and AMS 5629 is the usual specification. Forged bars, rings and near-net shapes.
Valves, wellhead, petrochemical
Stems, seat rings, bodies, bonnets and blocks for ball, gate, globe, check and plug valves, and pump parts where stress-corrosion cracking governs. Sour service needs separate qualification as set out in section 08. See forged valve parts.
Shafts and rotating parts
Pump and plunger-pump shafts, spindles, eccentric shafts and pins. Torque data is in Table 5. See forged shafts.
Nuclear and power
Reactor components and high-integrity fasteners and fittings, where strength, toughness and documented cleanliness are required together.
Tooling
Injection-moulding equipment, where the corrosion resistance of a stainless is wanted at hardness levels normally associated with tool steel.
Marine atmosphere
Components under sustained stress in marine air, aged at 538 °C or above, where the Kure Beach exposure data applies.
Where the grade is the wrong answer. It is not for prolonged service above roughly 593 °C, and the 288 to 482 °C band should be avoided for long holds. If you need strength at temperature rather than at ambient, look at A286. If the section is thin enough that transverse properties are not the deciding factor, 17-4PH or 15-5PH will usually be the better commercial choice.
Against the other PH grades
| Grade | UNS | Peak condition | Tensile minimum | Yield minimum | Distinguishing feature |
|---|---|---|---|---|---|
| PH13-8Mo | S13800 | H950 | 1517 MPa | 1414 MPa | Highest strength of the group, near-isotropic ductility in heavy sections, vacuum melted, molybdenum and aluminium additions, short-transverse reduction of area specified |
| 17-4PH | S17400 | H900 | 1310 MPa | 1170 MPa | The general industrial grade, lowest cost and widest availability, with H1150-M used for sour service |
| 15-5PH | S15500 | – | – | – | A lower-ferrite variant of 17-4PH developed for better transverse toughness in heavy forgings. Figures are on the 15-5PH page. |
| 17-7PH | S17700 | – | – | – | Semi-austenitic, formed in the annealed condition then transformation hardened. Mainly a sheet, strip and spring grade. |
PH13-8Mo minima from Rolled Alloys tabulating AMS 5864. 17-4PH minima as published on our own 17-4PH page from ASTM A564 and A705. The 15-5PH and 17-7PH cells are left blank rather than estimated; see those pages for verified figures.
The selection logic in practice: start with 17-4PH and move to PH13-8Mo when one of three things is true. The section is heavy and the drawing calls out transverse or short-transverse properties. The required strength is above what H900 will give. Or the specification itself names AMS 5629 or UNS S13800. The grade costs more and machines harder, and it earns that in those cases.
Testing and certification
Ultrasonic testing to ASTM A388 or EN 10228-3, which is the part covering ferritic and martensitic steel forgings, with magnetic particle testing to ASTM E709, chemistry by optical emission spectrometry to ASTM E415 with positive material identification, tensile testing to ASTM A370 and ISO 6892, and Charpy V-notch testing to minus 60 °C. EN 10204 3.1 as standard and 3.2 witnessed on request.
| Discipline | Equipment | Standard |
|---|---|---|
| Chemical analysis | Mobile optical emission spectrometer, SPECTROTEST TXC25 | ASTM E415 |
| Carbon and sulfur | Infrared carbon-sulfur analyser, HIR-9440D | ASTM E1019 |
| Alloy verification | Handheld analyser, X-Mwt3000TX | Positive material identification |
| Tensile | 600 kN hydraulic and 300 kN electronic universal testing machines | ASTM A370, ISO 6892 |
| Impact | Pendulum tester with low-temperature bath, JBN-300 and DWC-60 | ASTM A370, to minus 60 °C |
| Hardness | Leeb tester TH140 with conversion | ASTM A956, ASTM E140 |
| Ultrasonic | PXUT-3300, USM35XS and CTS-22 flaw detectors | ASTM A388, EN 10228-3 |
| Magnetic particle | CYE-3A crack detector | ASTM E709 |
| Metallography | XJP-6A microscope with mounting press, pre-grinder and polisher | ASTM E112 grain size |
Jiangyin Jiangnan Metal laboratory register. Tests outside this scope, such as ASTM A262, G28 or G48, impact below minus 60 °C, or bench Brinell and Rockwell where a portable instrument is not accepted, are placed with an accredited third-party laboratory and reported with the mill certificate. State the requirement at enquiry stage so it can be scheduled before shipment.
Surface treatment. Nitriding and other surface treatments can be applied where wear, galling or fatigue life govern. We quote surface hardness and case depth against the procedure agreed for the specific part and verify them on a coupon, rather than publishing a single figure, because the result depends on the aging condition, the process route and the section. The aging condition and the nitriding temperature interact: a cycle run above the aging temperature will overage the core. Send the requirement with the drawing.
How to order
Quotations are prepared from a drawing or a written specification. Sending the six items below in the first message removes a round trip and normally gets a price back within two working days. Minimum order is 10 kg with no minimum piece count. Normal lead time is 20 to 60 days, with UNS S13800 at the upper end because of the remelting step.
- Specification. ASTM A705 Type XM-13, AMS 5629 or EN 1.4534. Not ASTM B564.
- Melt route. Single melt, vacuum induction melting plus vacuum arc remelting, or electroslag remelted. Double melt is normal for this grade and affects price and lead time.
- Dimensions or drawing. For example 620 mm outside by 420 mm inside by 180 mm high, or a drawing or model as PDF, DWG, DXF or STEP with tolerances, surface roughness and any grain-flow requirement.
- Delivery condition. Condition A for onward fabrication, H1150M where machining governs, or the final aged condition from RH950, H950, H1000, H1025, H1050, H1100 or H1150.
- Heat treatment and testing. For example solution 927 °C then age H1000, ultrasonic to EN 10228-3, transverse Charpy at a stated temperature.
- Certification and destination. EN 10204 3.1 or 3.2 with the witnessing body if 3.2, any NACE review required, quantity, required date and destination port.
Send a PH13-8Mo drawing or specification
We melt, forge, heat-treat, machine and test UNS S13800 on one site in Jiangyin, Jiangsu. Customer audits and third-party inspection visits are welcome.
sales@steelforgepieces.com | 0086-189-2135-9659 | WhatsApp
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China
Wuxi Shuofang airport 30 km, Shanghai airports 160 km
Questions
Which specification should be cited on a forging order?
ASTM A705 Type XM-13, or AMS 5629 for aerospace work, which covers bars, wire, forgings, rings and extrusions. ASTM A564 Type XM-13 covers bars and shapes, ASTM A693 Grade XM-13 flat products, AMS 5864 sheet, strip and plate. ASTM B564 appears on several supplier pages for this grade, including the earlier version of this one, but it covers nickel-alloy forgings and does not apply. We accept orders under any of the correct designations and certify against the one named on the order.
What heat-treatment conditions exist for PH13-8Mo?
Condition A at 927 °C cooled below 16 °C, the refrigerated condition RH950, the single-step aged conditions H950, H1000, H1025, H1050, H1100 and H1150 at four hours each, and the double-aged H1150M at 760 °C for two hours followed by 621 °C for four hours. H900, H925 and H1075 belong to 17-4PH and are sometimes listed for this grade in error. Specified minimum tensile strength runs from 1,517 MPa in H950 to 931 MPa in H1150.
Is PH13-8Mo stronger than 17-4PH?
Yes. H950 has a specified minimum tensile strength of 1,517 MPa against 1,310 MPa for 17-4PH in H900, and RH950 reaches about 1,620 MPa typical. The bigger practical difference is ductility in heavy sections: carbon at 0.05 percent maximum, manganese and silicon at 0.10 percent each, sulfur at 0.008 percent and vacuum melting keep transverse and short-transverse reduction of area close to the longitudinal values, and AMS 5864 specifies the short-transverse figure separately.
How is the steel melted, and is double melting required?
UNS S13800 is normally double melted, vacuum induction melting followed by vacuum arc remelting, because the specification depends on very low carbon, manganese, silicon, sulfur, phosphorus and nitrogen and on low segregation. We run a 3 t vacuum induction furnace, a 6 t vacuum arc remelting furnace and 3 t and 6 t protective-atmosphere electroslag furnaces on the same site as the presses, so one heat number follows the part through to the certificate instead of starting from purchased billet.
What is the largest forging available in this grade?
Plant limits are 30 tonnes single-piece weight on the 6,300 t, 4,000 t and 2,000 t presses, and seamless rolled rings to 6,000 mm outside diameter on the 6 m mill, with 3 m and 1 m mills and an upset-and-punch route from 50 mm. For UNS S13800 the clean-melt ingot governs: the 3 t vacuum induction and 6 t vacuum arc remelting furnaces set the ceiling for double-melt material, so confirm the melt route with the enquiry and we will confirm the achievable size.
Can it be used in sour service to NACE MR0175 or ISO 15156?
Not by assumption. Those standards list precipitation-hardening stainless steels with named heat-treatment conditions, hardness ceilings and limits on hydrogen sulfide partial pressure, chloride concentration, pH and temperature, and acceptance is tied to the condition and the environment rather than the grade. Any part for hydrogen sulfide service has to be qualified against the current edition for the actual environment. State the hydrogen sulfide partial pressure, chloride level, pH and maximum temperature with the enquiry.
Can PH13-8Mo be welded?
Yes, by inert-gas shielded or resistance welding. Matching PH 13-8 filler gives weld properties close to the base metal, and an austenitic filler such as E or ER308L can be considered where high weld strength is not needed. Preheat is usually unnecessary. Welding in the solution-annealed condition is normal and the part can then be aged. Welding in the overaged H1150 condition is sometimes chosen where welding stresses are high, but material welded in that condition has to be re-solution treated before aging. Marine test data shows that aging straight after welding gives much poorer stress-corrosion performance than solution treating the welded assembly first.
What ultrasonic testing and certification can be supplied?
Ultrasonic testing to ASTM A388 or EN 10228-3, which is the part of EN 10228 for ferritic and martensitic steel forgings, with magnetic particle testing to ASTM E709 and liquid penetrant where specified. EN 10204 3.1 mill certificates are standard and EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TUV or your own inspector is available on request. The works holds CCS, BV, DNV, LR and NK approvals, and because the steel is melted here the certificate traces the part to its own heat number.
Why does the drawing say 1.4534 or X3CrNiMoAl13-8-2?
Those are the European material number and name for the same chemistry as UNS S13800. European projects, CE-marked equipment and European offshore work normally specify it that way. The order can be certified to the designation on the purchase order with the equivalents listed on the same certificate.
Sources
Property data here is taken from the published sources below and cross-checked against our own production test records. Where sources differ, the difference is noted in the table footnote. Values should be confirmed against the edition of the specification named on the purchase order before a design is released.
- Rolled Alloys, Data Sheet 13-8 Stainless, Bulletin 1022USe. Chemistry, physical properties, heat-treating parameters and minimum mechanical properties to AMS 5864.
- High Temp Metals, PH 13-8 Mo technical data. Type analysis, corrosion and stress-corrosion behaviour, physical properties, cycle definitions, typical longitudinal, transverse and torsional properties, workability and machining parameters.
- ASTM A564 and A564M Type XM-13; ASTM A705 and A705M Type XM-13; ASTM A693 Grade XM-13.
- SAE AMS 5629 and SAE AMS 5864.
- EN 10088-3 for 1.4534 and X3CrNiMoAl13-8-2; ASTM A388 and EN 10228-3 for ultrasonic testing; EN 10204 for certificate types.
- Jiangyin Jiangnan Metal Co., Ltd. equipment register, laboratory register and production records for all capability, size, lead-time and certification statements.
Citation: Jiangyin Jiangnan Metal Co., Ltd., PH13-8Mo Forgings, UNS S13800, AMS 5629, ASTM A705 Type XM-13, EN 1.4534, steelforgepieces.com, revised 3 October 2026, https://www.steelforgepieces.com/Stainless-Steel/PH13-8Mo.html