About PH Steel — 17-4 PH · 15-5 PH · 13-8 Mo Precipitation Hardening
Precipitation-hardening (PH) steels are a family of corrosion-resistant steels that can be hardened to very high strength levels by a relatively simple low-temperature ageing treatment (typically 480–620°C). Unlike conventional high-strength steels, PH grades retain excellent corrosion resistance (similar to 304 SS) and good weldability. 17-4 PH (630) is the most widely used, offering UTS values from 930 MPa (H1150) to 1310 MPa (H900) depending on ageing condition. 13-8 Mo provides superior transverse toughness for aerospace applications.
PH Steel Round Bar — 17-4 PH · 15-5 PH · 13-8 Mo
17-4 PH round bar in the annealed (Condition A) state is widely machined and then age-hardened by the end-user to the required H-condition. Pre-aged bars (H900 to H1150) are available for applications where post-machining heat treatment is impractical. 13-8 Mo bar is specified where a combination of ultra-high strength and maximum notch toughness is required.
Diameter
6 mm to 400 mm
Length
0.3 m to 6 m
Condition
Annealed (A) / H900 to H1150
| Diameter (mm) | Grade | Condition | UTS (MPa) | Application |
|---|---|---|---|---|
| 6–50 | 17-4 PH | Cond A (annealed) | 1000 | Machine then age |
| 6–50 | 17-4 PH | H900 | 1310 | Max strength parts |
| 6–200 | 17-4 PH | H1025 | 1140 | General aerospace |
| 6–200 | 17-4 PH | H1150 | 930 | Best toughness, corrosion |
| 6–200 | 15-5 PH | H900 / H1025 | 1310 | Short transverse toughness |
| 6–300 | 13-8 Mo | H950 / H1000 | 1380 | Maximum toughness aerospace |
Standards
PH Steel Sheet & Plate — 17-4 PH · 15-5 PH · 13-8 Mo
PH Steel Sheet & Plate are used for structural components that must be welded or formed before hardening. After forming, a single low-temperature ageing treatment transforms them to the required strength level without distortion. Used for aircraft skins, pressure vessel heads, and structural panels.
Sheet
0.3–6.0 mm
Plate
6–100 mm
Width × Length
Up to 2000 × 6000 mm
| Form | Thickness (mm) | Grade | Condition | UTS after H900 |
|---|---|---|---|---|
| Sheet | 0.3–6.0 | 17-4 PH / 15-5 PH | Cond A | Up to 1310 MPa |
| Plate | 6.0–40.0 | 17-4 PH | Cond A / H1025 | 930–1140 MPa |
| Plate | 6.0–100 | 13-8 Mo | Cond A | Up to 1380 MPa aged |
Standards
PH Steel Square Bar & Flat Bar — 17-4 PH · 15-5 PH
PH Steel Square Bar & Flat Bar are stocked for applications where rectangular cross-sections simplify machining setups for keys, splines, brackets, and structural members.
Square Bar
10×10 to 150×150 mm
Flat Bar
T:3–75 mm · W:10–200 mm
Condition
Annealed (Cond A)
| Section | Size Range | Condition |
|---|---|---|
| Square Bar | 10×10 to 150×150 mm | Cond A |
| Flat Bar | 3–75 mm × 10–200 mm | Cond A |
Standards
PH Steel Blocks & Forgings — 17-4 PH · 15-5 PH · 13-8 Mo
PH Steel Blocks, Billets & Forgings are used for complex structural aerospace parts, large valve bodies, and nuclear reactor internals. All forgings are UT tested and supplied with full heat treatment certifications.
Thickness
25–400 mm
W × L
Up to 2000 × 4000 mm
Condition
Cond A / H1025 / H1150
| Form | Grade | Thickness / Dia | Condition |
|---|---|---|---|
| Block (HR/Forged) | 17-4 PH | 25–400 mm | Cond A or aged |
| Forged Disc / Billet | 13-8 Mo | 50–500 mm dia | Cond A → age to spec |
| Near-net Forgings | 17-4 PH / 15-5 PH | Per drawing | Cond A → H900/H925/H1025 |
Standards
PH Steel Grade Reference — 17-4 PH · 15-5 PH · 13-8 Mo · H900–H1150
Chemical Composition — % by weight (max unless ranged)
| Grade | UNS | Cr | Ni | Cu | Mo | Nb+Ti | Others |
|---|---|---|---|---|---|---|---|
| 17-4 PH | S17400 | 15.0–17.5 | 3.0–5.0 | 3.0–5.0 | — | Nb: 0.15–0.45 | — |
| 15-5 PH | S15500 | 14.0–15.5 | 3.5–5.5 | 2.5–4.5 | — | Nb: 0.15–0.45 | — |
| 13-8 Mo | S13800 | 12.25–13.25 | 7.5–8.5 | — | 2.0–2.5 | — | Al: 0.90–1.35 |
Mechanical Properties — Annealed / Standard Condition
| Grade | Condition | UTS (MPa) min | 0.2% YS (MPa) min | Elong % min | Hardness HRC |
|---|---|---|---|---|---|
| 17-4 PH | Cond A (annealed) | 1000 | 790 | 10 | 33 |
| 17-4 PH | H900 | 1310 | 1170 | 10 | 40 |
| 17-4 PH | H925 | 1170 | 1070 | 10 | 38 |
| 17-4 PH | H1025 | 1070 | 1000 | 12 | 35 |
| 17-4 PH | H1075 | 1000 | 930 | 13 | 32 |
| 17-4 PH | H1150 | 930 | 724 | 16 | 28 |
| 15-5 PH | H900 | 1310 | 1170 | 10 | 40 |
| 13-8 Mo | H950 | 1380 | 1240 | 10 | 43 |
| 13-8 Mo | H1000 | 1240 | 1140 | 12 | 40 |
Grade Selection Guide
| Condition | Strength Level | Best For |
|---|---|---|
| H900 | Maximum (1310 MPa) | Springs, valves, turbine components |
| H925 | Very High (1170 MPa) | Gears, fasteners, shafts |
| H1025 | High (1070 MPa) | General aerospace structural |
| H1150 | Moderate (930 MPa) | Best weldability & toughness |
Why Buy PH Steel from Suresh Metals?
Ready Stock — No Lead Times
All grades held in ready stock at our Mumbai facility. Same-day or next-day dispatch on standard sizes.
Mill Test Certificates (MTC)
Every consignment includes a heat-traceable MTC. NACE, PMI, third-party inspection on request.
Pan-India Delivery & Exports
Domestic delivery to any factory gate. Export to Middle East, SE Asia & Africa — sea-worthy packing, LC & TT accepted.
Cut-to-Size Processing
Plasma, waterjet, shearing, and sawing services — receive material sized to your drawing.
37+ Years of Expertise
Established 1987. Our team advises the right grade and form for your exact application.
Competitive Pricing
Direct mill sourcing and volume stock means best-in-market rates. Quote within 4 business hours.