Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASTM A1082/A1082M Grade S15700 | 15-7 PH Stainless Steel
High-strength precipitation hardening steel for springs and aerospace components
Grade S15700 (UNS S15700) is a precipitation hardening martensitic stainless steel, commonly known as 15-7 PH, containing 15% chromium and 7% nickel with aluminum additions that enable age hardening to achieve exceptional strength levels up to 230 ksi while maintaining good corrosion resistance and excellent spring properties. This PH grade is widely used in aerospace components, springs, clips, fasteners, and high-performance mechanical parts requiring high strength-to-weight ratio, fatigue resistance, and moderate corrosion protection. S15700 can be supplied in solution-annealed condition for forming and fabrication, then heat treated to develop high hardness and strength through precipitation of intermetallic compounds. The material offers superior performance to 17-7 PH in applications requiring maximum strength with adequate corrosion resistance in mildly corrosive environments.
ASTM A1082/A1082M Grade S15700 Chemical Composition
| Grades | UNS Designation | Type | C | Mn | P | S | Si | Cr | Ni | Mo | N | Other ElementsB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A1082/A1082M Precipitation Hardening Grades | S15700 | 632 | 0.09 | 1.00 | 0.040 | 0.030 | 1.00 | 14.0-16.0 | 6.5-7.7 | 2.00-3.00 | . . . | Al 0.75-1.50 |
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ASTM A1082/A1082M Grade S15700 Solution Treatment
| UNS Designation | Type | Rockwell, max | Brinell max |
|---|---|---|---|
| S15700 | 632 | 100 HRB | 269 |
ASTM A1082/A1082M Grade S15700 Age Hardening Treatment
| Type | Condition | Suggested Hardening and/or Aging Temperatures, Time at Temperature, and Quench Media °F [°C] | Tensile Strength ksi [MPA] | Yield Strength ksi [MPA] | Elongation in 2" [50 mm] or 4D % | Reduction of Area, % | Rockwell, HRC | Brinell |
|---|---|---|---|---|---|---|---|---|
| 632 | RH950 | 1750 [955] for 10 min. to 1 h, rapidly cool to room temperature. Cool within 24 hrs. to -100 ± 10 [-75 ± 5], hold 8 hrs. min. Warm in air to room temperature. Heat to 950 [510] hold 1 h, air cool. | 200 [1380] | 175 [1210] | 7 | 25 | 44 | 415 |
| 632 | Th4050 | 1400 [760] for 90 min. Cool to 55 ± 5 [15 ± 3] within 1 h, hold 1/2 h min., heat to 1050 [565], hold for 90 min., air cool | 180 [1240] | 160 [1100] | 8 | 25 | 38 | 375 |
ASTM A1082/A1082M Markings
| UNS Designation | Type | Condition | Grade Symbol |
|---|---|---|---|
| S15700 | 632 | . . . | TB 157 |
| S15700 | 632 | RH95 | TB 157A |
| S15700 | 632 | Th4050 | TB 157B |
Frequently Asked Questions
What is 15-7 PH (S15700)?
15-7 PH (S15700) is a stainless steel grade covered under ASTM A1082/A1082M for high-strength bolting in special-purpose applications such as pressure vessels. UNS designation S15700. Available as bolts, studs, screws and nuts manufactured by TorqBolt for global oil/gas/nuclear/power/marine sectors.
What are the mechanical properties of 15-7 PH (S15700) per ASTM A1082?
Mechanical property requirements for S15700 are defined in ASTM A1082 Table 2 (PH grade solution treatment) or Table 4 (duplex annealed condition). Properties vary by treatment condition - refer to the bolting specification for the H-condition (PH) or annealed yield/tensile/elongation/hardness requirements applicable to your order.
Is 15-7 PH (S15700) suitable for sour service (NACE MR0175)?
Refer to NACE MR0175 / ISO 15156 Tables A.16-A.19. Most A1082 duplex grades are permitted at ≤28 HRC; PH grades require condition-specific qualification (typically H1150 for 17-4 PH at 28 HRC). TorqBolt supplies sour-service certified product on request with full PMI + hardness traceability.
What ASME / ISO dimensional standards can 15-7 PH (S15700) be supplied to?
This grade is available across the full ASME and ISO bolting dimensional standards covered on this site - ASME B18.2.1 (hex bolts, hex cap screws, lag screws), B18.2.2 (hex nuts, square nuts, lock nuts), B18.3 (socket head cap screws), B18.31.2 (clamping studs), B16.5 (flange stud bolts), ISO 4032 / 4033 / 4035 (metric nuts), and metric B18.2.3.xM / B18.2.4.xM series.
References & Standards
- ASTM A1082 / A1082M - Standard Specification for High-Strength Precipitation-Hardening and Duplex Stainless Steel Bolting for Special-Purpose Applications (current edition 2016, active)
- ASTM A962 / A962M - General Requirements for Special-Purpose Bolting Materials
- ASTM A370 - Mechanical Testing of Steel Products
- NACE MR0175 / ISO 15156 - Sour-service hardness limits for petroleum & natural gas industries
- ASME B18 series - Dimensional standards for bolts, screws, nuts, studs
- ISO 4032 / 4033 / 4035 - Metric hexagon nut dimensional standards
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