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 S35500 | Grade 634 PH Stainless Steel
High-strength semi-austenitic PH steel combining durability with superior corrosion resistance
Grade S35500 (UNS S35500) is a semi-austenitic precipitation-hardening stainless steel, commonly known as AM 355 or Grade 634, designated as ASTM A1082/A1082M, containing 15% chromium and 4% nickel with molybdenum additions that enable it to achieve high strength and hardness through heat treatment while maintaining excellent corrosion resistance. This premium PH grade is extensively used in aerospace components, gas turbine parts, high-performance fasteners, and industrial mechanical components where high strength combined with resistance to atmospheric corrosion and oxidation at elevated temperatures is critical. S35500 offers a good balance of properties, maintaining high toughness and strength from cryogenic temperatures up to 900°F (480°C), making it ideal for turbine blades, compressor discs, and demanding mechanical assemblies.
ASTM A1082/A1082M Grade S35500 Chemical Composition
| Grades | UNS Designation | Type | C | Mn | P | S | Si | Cr | Ni | Mo | N | Other ElementsB |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A1082/A1082M Precipitation Hardening Grades | S35500 | 634 | 0.10-0.15 | 0.50-1.25 | 0.040 | 0.030 | 0.50 | 15.0-16.0 | 4.0-5.0 | 2.5-3.2 | 0.07-0.13 | Cb 0.10-0.50 |
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ASTM A1082/A1082M Grade S35500 Solution Treatment
| UNS Designation | Type | Solution Treatment °F [°C] | Brinell, maximum |
|---|---|---|---|
| S35500 | 634 | Hold at ≤ -100 [-73] for at least 3 hours | 363 |
ASTM A1082/A1082M Grade S35500 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 |
|---|---|---|---|---|---|---|---|---|
| 634 | h4000 | 1750 [955] for 10 min. to 1 h, water quench. Cool to -100 [75] min., hold 3 hrs. min. Temper at 1000 [540] hold for 3 h min, air cool. | 170 [1170] | 155 [1070] | 12 | 25 | 37 | 341 |
ASTM A1082/A1082M Markings
| UNS Designation | Type | Condition | Grade Symbol |
|---|---|---|---|
| S35500 | 634 | . . . | TB 355 |
| S35500 | 634 | h4000 | TB 355A |
Frequently Asked Questions
What is AM-355 (S35500)?
AM-355 (S35500) is a stainless steel grade covered under ASTM A1082/A1082M for high-strength bolting in special-purpose applications such as pressure vessels. UNS designation S35500. Available as bolts, studs, screws and nuts manufactured by TorqBolt for global oil/gas/nuclear/power/marine sectors.
What are the mechanical properties of AM-355 (S35500) per ASTM A1082?
Mechanical property requirements for S35500 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 AM-355 (S35500) 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 AM-355 (S35500) 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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