15-5PH is a martensitic, precipitation-hardening chromium-nickel-copper stainless steel, designated UNS S15500, W.Nr. 1.4545 and ASTM Type XM-12. It holds roughly 15 % chromium and 5 % nickel with 2.5 to 4.5 % copper, and reaches high strength and hardness through a single low-temperature ageing treatment after solution annealing.
The grade is a remelted variant of 17-4PH, developed to give better transverse toughness and more even properties in heavy sections, which is what makes it suitable for forgings. Jiangyin Jiangnan Metal Co., Ltd. forges 15-5PH open-die parts and seamless rolled rings to ASTM A705/A705M Type XM-12 and AMS 5659 at its plant in Jiangyin, Jiangsu, China.
What is 15-5PH stainless steel?
15-5PH belongs to the precipitation-hardening group of stainless steels, which sits between the martensitic and ferritic classes. Strength comes from fine copper-rich particles that form during ageing, not from a high-carbon quench or from cold work.
Hardening is a one-step cycle: hold at the ageing temperature, then air cool. Distortion stays low, so parts can be rough machined before ageing. The ageing temperature sets the property level. A lower ageing temperature gives higher strength and lower toughness.
Corrosion resistance is moderate. In most media 15-5PH performs better than the 410-type martensitic stainless steels but does not reach 304 or 316, and like other PH grades it is attacked by chlorides. Useful corrosion resistance is normally quoted up to about 600 °F (316 °C).
For forged parts the practical gain over 17-4PH is the remelted structure. 15-5PH is supplied consumable-electrode remelted, either ESR to AMS 5659 Type 2 or vacuum melted to Type 1. That route lowers segregation and inclusion content and improves short-transverse ductility in thick sections.
15-5PH standards and equivalent designations
State the specification on the purchase order. For forgings the governing ASTM specification is A705/A705M. A564 covers bar and shapes and A693 covers sheet and strip. All three use the same type designation, XM-12.
| Product form | Specification | Type or grade |
|---|---|---|
| Forgings | ASTM A705 / A705M | XM-12 |
| Bar, shapes | ASTM A564 / A564M | XM-12 |
| Sheet, strip, plate | ASTM A693 | XM-12 |
| Aerospace bar and forgings | AMS 5659 | Type 1 vacuum melt, Type 2 ESR |
| Aerospace sheet, strip, plate | AMS 5862 | Not applicable |
| Welding wire | AMS 5826 | Not applicable |
| General requirements | ASTM A484 | Not applicable |
| System | Designation |
|---|---|
| UNS (USA) | S15500 |
| Werkstoff-Nr. (Germany) | 1.4545 |
| EN name | X5CrNiCu15-5 |
| ASTM type | XM-12 |
| Common trade name | 15-5 PH, Alloy 15-5 |
UNS S17400, 1.4542, X5CrNiCuNb16-4, AISI 630 and SUS 630 are not equivalents of 15-5PH. They all designate 17-4PH, a separate grade with a different chromium and niobium balance. We forge both, so confirm which one your drawing calls for.
15-5PH chemical composition
The limits below follow AMS 5659. The niobium (columbium) minimum of 0.15 % applies under ASTM A705 Type XM-12.
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.07 max |
| Silicon (Si) | 1.00 max |
| Manganese (Mn) | 1.00 max |
| Phosphorus (P) | 0.030 max |
| Sulphur (S) | 0.015 max |
| Chromium (Cr) | 14.00 to 15.50 |
| Nickel (Ni) | 3.50 to 5.50 |
| Copper (Cu) | 2.50 to 4.50 |
| Niobium + Tantalum (Nb+Ta) | 0.15 to 0.45 |
| Molybdenum (Mo) | 0.50 max |
| Iron (Fe) | Balance |
15-5PH mechanical properties by condition
Minimum room-temperature properties for AMS 5659 bar and forgings. Metric figures are converted from the ksi minima and rounded.
| Condition | Tensile min (ksi) | Tensile min (MPa) | Yield 0.2 % min (ksi) | Yield 0.2 % min (MPa) | Elongation min (%) | Reduction of area min (%) | Hardness (HB) |
|---|---|---|---|---|---|---|---|
| Condition A | Not specified | Not specified | Not specified | Not specified | Not specified | Not specified | 363 max |
| H900 | 190 | 1310 | 170 | 1170 | 10 | 35 | 388 to 444 |
| H925 | 170 | 1170 | 155 | 1070 | 10 | 38 | 375 to 429 |
| H1025 | 155 | 1070 | 145 | 1000 | 12 | 45 | 331 to 401 |
| H1075 | 145 | 1000 | 125 | 860 | 13 | 45 | 311 to 375 |
| H1100 | 140 | 965 | 115 | 790 | 14 | 45 | 302 to 363 |
| H1150 | 135 | 930 | 105 | 725 | 16 | 50 | 277 to 352 |
Properties of heavy forgings depend on section size and on where the test piece is taken. For large rings, discs and shafts the ruling section and sampling position are agreed at enquiry stage, and testing is carried out on prolongations taken from the forging itself.
15-5PH physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.80 g/cm³ | 0.282 lb/in³ |
| Modulus of elasticity | 196 GPa | 28 427 ksi |
| Poisson's ratio | 0.27 to 0.30 | 0.27 to 0.30 |
| Thermal conductivity (150 °C) | 17.8 W/m·K | 124 BTU·in/hr·ft²·°F |
| Coefficient of thermal expansion | 10.4 µm/m·°C | 5.78 µin/in·°F |
15-5PH heat treatment
15-5PH is solution annealed and then aged. Ageing is a single-step, air-cooled cycle, so the full treatment can follow rough machining with little distortion.
| Condition | Temperature | Soak time | Cooling |
|---|---|---|---|
| Condition A (solution) | 1038 °C / 1900 °F | 0.5 h | Air |
| H900 | 482 °C / 900 °F | 1 h | Air |
| H925 | 496 °C / 925 °F | 4 h | Air |
| H1025 | 552 °C / 1025 °F | 4 h | Air |
| H1075 | 579 °C / 1075 °F | 4 h | Air |
| H1100 | 593 °C / 1100 °F | 4 h | Air |
| H1150 | 621 °C / 1150 °F | 4 h | Air |
| H1150M | 760 °C / 1400 °F then 621 °C / 1150 °F | 2 h + 4 h | Air after each |
Annealing and hot working
Annealing is carried out at 1038 °C (1900 °F) for one hour followed by rapid cooling. All common hot-working methods apply. After hot work the material is annealed so that it responds correctly to the later ageing treatment.
Surface treatment
Where higher surface hardness, wear resistance or anti-galling behaviour is wanted, nitriding of 15-5PH forgings can be arranged through qualified subcontractors. Case hardness and case depth depend on the process chosen and on the ageing condition of the part, so we confirm them against the treater's qualified procedure instead of quoting a fixed figure. Mark the surface requirement on the drawing and we will confirm feasibility before order.
15-5PH forged product forms
Every shape below is open-die forged or ring rolled at our Jiangyin plant and supplied as forged, rough machined or machined to drawing.
Seamless rolled rings
Ring-rolled and forged rings for pumps, valves and machinery, including slewing and large-diameter bearing rings.
Forged shafts
Step shafts, pump shafts, plunger shafts, spindles, eccentric shafts and crankshafts.
Forged flanges
Flanges, tube sheets, nozzles and blind blanks for vessels and heat exchangers.
Discs and blocks
Forged discs, disks, blocks, plates and gear blanks.
Hollow forgings
Hollow bars, sleeves, bushings, pipes, tubes, cylinders, hubs, casings and housings.
Forged bars
Round, square, rectangular, flat and hex bars, plus forging stock.
Valve components
Valve stems, seat rings, bodies, blocks and bonnet forgings.
Gear forgings
Gear blanks, pinion blanks and coupling forgings for power transmission.
Near-net shapes
Contoured and stepped preforms that cut machining allowance on costly PH stainless.
15-5PH production route
- Electric arc furnace (EAF) melting. Scrap and ferro-alloys melted to the required chemistry.
- Ladle refining (LF / VOD). Chemistry trimmed, carbon and sulphur reduced, inclusion level lowered.
- Electroslag remelting (ESR). Consumable-electrode remelting to AMS 5659 Type 2 for a clean, low-segregation ingot. Vacuum-melted material to Type 1 on request.
- Open-die forging or ring rolling. Ingot forged to shape with enough forging ratio to give a sound, fine-grained structure.
- Solution annealing and ageing. Condition A followed by the specified H-condition.
- Inspection and testing. Chemical analysis, mechanical tests, hardness and ultrasonic testing where specified.
- Marking and packing. Grade, heat number and length stamped on each piece, with the colour marking you ask for.
Machining, welding and forming
Machining
15-5PH can be machined in any of its attainable conditions. For the best tool life, machining in the H1150M condition is recommended. A common production sequence is to rough machine in Condition A or an overaged condition, age to the required H-condition, then finish machine. That keeps cutting forces down while still holding final tolerances. Machining fully aged H900 material is hard work and calls for rigid setups, reduced speeds and suitable carbide grades.
Welding
The grade is welded by shielded fusion or resistance methods. AWS E/ER630 is the standard filler metal. Welded assemblies should be re-solution treated and aged, or at least re-aged, to restore properties in the heat-affected zone.
Forming
15-5PH is not suited to cold working and can be formed only in a mild manner. The best results are obtained in the overaged condition.
Applications of 15-5PH forgings
15-5PH is specified for parts that need high strength together with corrosion resistance in moderately aggressive service: gears, valves, fittings, fasteners and shafts, and a wide range of aircraft components. Forged applications we supply include:
- Pumps. Chemical pump shafts, plunger pump components, rolled rings and sleeves.
- Valves. Stems, seat rings, bodies and blocks for ball, gate, globe, check and plug valves.
- Pressure equipment. Flanges, tube sheets, nozzles and shell components for vessels and shell-and-tube heat exchangers.
- Oil and gas. Subsea and deepwater production hardware, wellhead and Christmas tree components.
- Rotating equipment. Compressor and turbine parts, gear blanks, spindles and gearbox shafts.
- Aerospace and nuclear. Engine parts, airframe fittings and reactor components needing high transverse strength and toughness.
- Heavy and process machinery. Forged rolls, wheels, manifolds, crankshafts and mill components.
15-5PH vs 17-4PH: which to specify
The two grades are close relatives and reach similar strength at matching H-conditions. The differences that matter for forgings are structural rather than large.
| Attribute | 15-5PH (S15500) | 17-4PH (S17400) |
|---|---|---|
| Werkstoff-Nr. | 1.4545 | 1.4542 |
| ASTM type or grade | XM-12 | 630 |
| Chromium | 14.00 to 15.50 % | 15.5 to 17.5 % approx. |
| Melt practice | Consumable-electrode remelted, ESR or vacuum | Commonly air melted |
| Transverse toughness | Higher, which is why the grade was developed | Lower in the short-transverse direction |
| Heavy sections | More even properties | Greater property fall-off |
| Corrosion resistance | Broadly comparable. Both better than 410, both below 304 and 316, both vulnerable to chlorides. | |
Specify 15-5PH when the part is thick, heavily loaded across the grain, or when the drawing calls for remelted material. Specify 17-4PH where cost matters more and the section is light. Published data does not agree on whether 15-5PH holds a real corrosion advantage over 17-4PH, and several sources treat the two as equal on that point, so corrosion resistance alone is a weak basis for choosing between them.
Ordering, testing and quality documents
| Minimum order | 12 tonnes |
|---|---|
| Pricing | Quoted per enquiry against grade, drawing, delivery condition and quantity |
| Payment | 30 % advance by T/T, balance before shipment against shipping documents, or irrevocable L/C at sight |
| Delivery condition | Condition A, or aged to H900, H925, H1025, H1075, H1100, H1150 or H1150M |
| Ultrasonic testing | EN 10228-3, SEP 1921 or ASTM A388 to the agreed acceptance class |
| Certification | EN 10204 3.1 mill certificate, or 3.2 with third-party witness (TUV, SGS, BV, Lloyd's) |
| Other NDT | Liquid penetrant and magnetic particle inspection on request |
| Marking | Grade, heat number and length stamped on each piece, colour marking as required |
For a quotation, send the grade and standard, drawing or dimensions, quantity, delivery condition and testing requirements to sales@steelforgepieces.com.
Request a 15-5PH forging quotation
Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China.
Send your drawing or dimensions and we will quote rings, shafts, flanges, discs and bars in 15-5PH to ASTM A705 XM-12 or AMS 5659.
15-5PH frequently asked questions
What is 15-5PH stainless steel?
15-5PH is a martensitic precipitation-hardening chromium-nickel-copper stainless steel, designated UNS S15500 and W.Nr. 1.4545. It holds about 14.0 to 15.5 % chromium, 3.5 to 5.5 % nickel and 2.5 to 4.5 % copper, and reaches high strength and hardness through solution annealing followed by a single low-temperature ageing treatment. It offers good transverse toughness and ductility with moderate corrosion resistance.
Which standard covers 15-5PH forgings?
ASTM A705/A705M, Standard Specification for Age-Hardening Stainless Steel Forgings, Type XM-12. Bar and shapes fall under ASTM A564 Type XM-12, sheet and strip under ASTM A693 Type XM-12, and aerospace bar and forgings under AMS 5659, Type 1 vacuum melted or Type 2 ESR. ASTM B564 is sometimes quoted by mistake. That specification covers nickel alloy forgings and does not apply to 15-5PH.
What is the equivalent of 15-5PH?
15-5PH is designated UNS S15500, W.Nr. 1.4545, X5CrNiCu15-5 and ASTM Type XM-12. It is not equivalent to UNS S17400, 1.4542, X5CrNiCuNb16-4, AISI 630 or SUS 630, all of which designate the separate grade 17-4PH.
What is the difference between 15-5PH and 17-4PH?
15-5PH was developed from 17-4PH to give better toughness, mainly in the short-transverse direction, and more even properties in larger cross-sections. It is supplied consumable-electrode remelted by ESR or vacuum melting, while 17-4PH is commonly air melted. Strength at matching H-conditions is similar and corrosion resistance is broadly comparable, both above 410 and below 304 and 316.
What heat treatment conditions are available for 15-5PH?
Condition A, solution annealed at 1038 °C (1900 °F) and air cooled, plus the aged conditions H900, H925, H1025, H1075, H1100, H1150 and H1150M. H900 gives the highest strength at 190 ksi (1310 MPa) minimum tensile. H1150 gives the highest ductility at 135 ksi (930 MPa) minimum tensile with 16 % elongation. Solution treatment and ageing are done in house.
What are the mechanical properties of 15-5PH in H1025?
In the H1025 condition, AMS 5659 bar and forgings have a minimum tensile strength of 155 ksi (1070 MPa), a minimum 0.2 % yield strength of 145 ksi (1000 MPa), minimum elongation of 12 %, minimum reduction of area of 45 %, and hardness of 331 to 401 HB.
Is 15-5PH easy to machine?
It can be machined in all attainable conditions, and the H1150M condition gives the best tool life. Many shops rough machine in Condition A or an overaged condition, age to the required H-condition, then finish machine. Fully aged H900 material is hard and demanding to cut, so rigid setups and reduced speeds are needed.
Can 15-5PH be welded?
Yes. 15-5PH is welded by shielded fusion or resistance methods using AWS E/ER630 filler metal. Weldments should be re-solution treated and aged, or at least re-aged, to restore properties in the heat-affected zone.
Can you nitride 15-5PH forgings?
Yes. Nitriding can be arranged through qualified treaters where high surface hardness, wear resistance or anti-galling behaviour is required. Case hardness and case depth depend on the process used and on the ageing condition of the part, so they are confirmed against the treater's qualified procedure before the order is accepted rather than quoted as a standard figure.
Where can I buy 15-5PH forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. manufactures 15-5PH open-die forgings at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. Products include seamless rolled rings, shafts, flanges, discs, sleeves, bushings, hollow bars, tube sheets and forged bars. Tel +86 189 2135 9659, email sales@steelforgepieces.com.
What are the MOQ and payment terms?
Minimum order is 12 tonnes. Payment is 30 % advance by T/T with the balance before shipment against shipping documents, or an irrevocable L/C at sight. Prices are quoted per enquiry, since they depend on grade, drawing, delivery condition, quantity and the nickel and alloy surcharge at the time of order.
What testing and certification do you provide?
Chemical analysis, mechanical testing on prolongations taken from the forging, and hardness testing as standard. Ultrasonic testing can be carried out to EN 10228-3, SEP 1921 or ASTM A388, with liquid penetrant and magnetic particle inspection on request. Certificates are issued to EN 10204 3.1, or 3.2 with third-party witness.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China. We produce forged bars, shafts, hollow forgings, seamless rolled rings, discs, flanges and blocks in carbon steel, alloy steel, tool steel, stainless and duplex stainless steel and nickel alloys, and export to customers worldwide.
Contact: +86 189 2135 9659 · sales@steelforgepieces.com