A286 Button Head Cap Screws
RAYCHIN SPECIALTY METALS FASTENERS: BOLTS, NUTS, SCREWS, WASHERS, STUDS, THREADED RODS, U-BOLT, J-BOLTS
STANDARD AND CUSTOMIZED, SMALL BATCH AND LARGE BATCH, IMPERIAL AND METRIC
A286 / Alloy 660 for excellent high temperature oxidation resistance
Excellent high temperature oxidation resistance to 1300°F / 700°C
Maintains high strength at elevated temperatures
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RAYCHIN LIMITED
Specialist in A286 Button Head Cap Screws · Low Profile · Hex Socket · Torx · CustomA286 Button Head Cap Screws: Low Profile, Hex Socket, Torx & Custom Configurations
RAYCHIN LIMITED is a recognized expert in A286 button head cap screws — from A286 hex socket button head screws, A286 low profile button head screws, A286 Torx button head screws to custom non-standard button head screw configurations. A286 (UNS S66286) is an iron-nickel-chromium superalloy strengthened by precipitation hardening. Also designated as Alloy 660, it maintains exceptional strength and oxidation resistance up to 700°C (1292°F), making it the preferred material for high-temperature button head screw applications in gas turbines, jet engines, and aerospace assemblies. The button head design features a low-profile domed head with internal drive, providing a smooth appearance while requiring less head height than standard cap screws. With a head height approximately 50% lower than standard socket head cap screws, these are ideal for limited clearance applications in high-temperature equipment. Our portfolio includes button head cap screws manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards. Engineered for extreme environments where exceptional high-temperature strength, corrosion resistance, and space constraints are critical. A286 button head cap screws are available in solution annealed and aged conditions with precision rolled threads and full traceability.
Complete Range of A286 Button Head Cap Screws
A286 Hex Socket Button Head Cap Screws
A286 hex socket button head cap screws featuring low-profile domed head with hexagon socket drive. Manufactured to DIN 7380, ISO 7380, and ASME B18.3 specifications. The hex socket drive provides positive engagement and allows for higher torque capacity than slotted or Phillips drives. The button head design offers a head height approximately 50% lower than standard socket head cap screws, ideal for limited clearance applications in gas turbines, jet engine components, and high-temperature processing equipment. Available in sizes from #0 to 1" (M2 to M24). Heat treated in solution annealed and aged condition for exceptional high-temperature strength up to 700°C.
A286 Torx Button Head Cap Screws
A286 Torx button head cap screws with hexalobular drive for maximum torque transmission and cam-out resistance. The Torx drive provides superior torque transfer and extended tool life compared to hex socket drives, making them ideal for high-vibration aerospace applications. Available with Torx drive sizes T6 through T60. Security Torx variants with center pins available for anti-tamper applications in high-temperature equipment. The low-profile button head design provides a smooth appearance while maintaining the exceptional high-temperature strength of A286 up to 700°C.
A286 Low Profile Button Head Screws
A286 low profile button head screws with reduced head height for extremely limited clearance applications in high-temperature environments. Designed to customer specifications with head heights 20-30% lower than standard button head screws. Ideal for compact assemblies in gas turbine instrumentation, aerospace components, and high-temperature processing equipment where space is at a premium. Available with hex socket or Torx drive. Maintains the exceptional high-temperature strength of A286 up to 700°C.
A286 Metric Button Head Cap Screws
A286 metric button head cap screws manufactured to DIN 7380 and ISO 7380 standards. Available in coarse and fine thread pitches from M2 to M24. Precision rolled threads with Class 6g tolerance. The button head design provides a smooth appearance with head height approximately 50% of standard socket head cap screws. Ideal for international high-temperature projects requiring metric fasteners with exceptional strength up to 700°C. Widely used in European gas turbine and aerospace applications.
A286 Aerospace & Military Button Head Screws
A286 button head screws manufactured to NAS, AN, and MS specifications including NAS 1351, NAS 1352, and MS specifications. Available with UNJF-3A threads per MIL-S-8879 for enhanced fatigue life. Shot peened per aerospace requirements and available with silver plating for anti-galling. Full traceability with material certification and third-party testing available. Ideal for aerospace exhaust systems, jet engine components, and high-temperature structural applications requiring low-profile fasteners with exceptional strength up to 700°C.
Custom & Specialty A286 Button Head Cap Screws
Need a special head diameter, reduced head height, or custom drive configuration for your high-temperature application? RAYCHIN engineers work with you to produce custom A286 button head cap screws to your drawing. Expert heat treatment (solution annealed at 982°C followed by precipitation hardening at 718°C for 16 hours) precisely controlled for each batch. Manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS standards. Custom drive depths and tamper-resistant configurations available.
Button Head Design Advantages for A286 Cap Screws
Low Profile
Button head screws have a head height approximately 50% lower than standard socket head cap screws, ideal for confined spaces and low-clearance applications in gas turbines and aerospace equipment.
Wide Bearing Surface
The button head provides a larger bearing surface compared to other low-profile heads, making it ideal for clamping thin materials without counter-boring in high-temperature assemblies.
Smooth Appearance
The domed head provides a smooth, finished appearance that is aesthetically pleasing for visible aerospace and gas turbine components.
Internal Drive
Hex socket or Torx internal drives allow for positive engagement and higher torque capacity than external drives, with reduced risk of cam-out during high-temperature installation.
Manufacturing Standards for A286 Button Head Cap Screws
RAYCHIN LIMITED manufactures A286 button head cap screws to the following national and international standards, ensuring full compliance for projects worldwide. Both standard and non-standard custom configurations are available.
International Standards & Global Designations for A286 Button Head Cap Screws
To serve clients worldwide, RAYCHIN LIMITED manufactures A286 button head cap screws from material conforming to the following national and international specifications. This ensures full compliance for projects in the Americas, Europe, Asia, and the Middle East.
UNS S66286 Alloy 660 ASTM A453 AMS 5732 AMS 5737 NACE MR0175 1.4980 DIN 7380 ISO 7380
Chemical Composition (Weight %) – A286 Superalloy (UNS S66286 / 1.4980)
Our A286 button head cap screws are produced from melts that strictly conform to the limits below per ASTM A453 / AMS 5731. The high nickel and chromium content provide excellent oxidation resistance, while titanium and aluminum enable precipitation hardening through gamma-prime (γ') phase formation. Molybdenum and vanadium contribute to solid solution strengthening, and boron enhances creep resistance.
Expert note: The combination of titanium and aluminum promotes the formation of Ni₃(Al,Ti) gamma-prime precipitates during aging, which provide A286 with its exceptional high-temperature strength. The addition of boron (0.001-0.010%) significantly improves creep resistance by strengthening grain boundaries. With nickel content of 24-27%, A286 offers excellent resistance to chloride stress corrosion cracking and maintains a stable austenitic structure from cryogenic temperatures up to 700°C.
Complete Mechanical Properties of A286 Button Head Cap Screws (per ASTM A453)
A286 button head cap screws are supplied in the solution annealed and precipitation hardened condition (982°C solution treat + 718°C age for 16 hours). ASTM A453 defines multiple classes for different strength levels and size ranges. The data below represent minimum requirements per ASTM A453/A453M. Screws are proof load tested to ensure compatibility with mating nuts.
Tensile Requirements by Class – ASTM A453 Grade 660
Hardness Requirements
Stress Rupture Properties (650°C / 1200°F)
A critical requirement for high-temperature fasteners is stress rupture resistance. Per ASTM A453, Class A, B, and C materials must meet the following:
Research confirms that A286 maintains anti-tensile strength not less than 885 MPa at 500°C with stress retention greater than 88.35%, making it the optimal choice for high-temperature fastener applications.
Temperature-Dependent Yield Strength
The following table shows typical yield strength (0.2% offset) at elevated temperatures for A286 in the fully heat-treated condition.
At 500°C, A286 maintains excellent stress retention, with studies showing stress retention rates exceeding 88.35% at this temperature.
Thermal Expansion Advantage of A286 Button Head Cap Screws
A286 is specifically designed for bolting austenitic stainless steel components operating at elevated temperatures. Its thermal expansion coefficient closely matches that of 304/316 stainless steels, preventing loss of preload during thermal cycling – a critical feature for button head screws used in high-temperature assemblies where maintaining clamping force is essential.
This expansion match is critical for maintaining preload and preventing loosening in high-temperature applications such as gas turbine components, exhaust systems, and heat treatment fixtures. Standard alloy steel fasteners expand less than the surrounding components, leading to loss of preload and potential failure. A286 eliminates this mismatch.
API 6A & NACE MR0175 Compliance
A286 button head cap screws are widely used in oil and gas applications requiring sour service resistance. Per API 6A and API 20F, A286 Grade 660 Class D is approved for H₂S service with maximum hardness of 35 HRC.
Heat Treatment & Microstructural Stability
Optimal mechanical properties in A286 button head cap screws are achieved through a two-step heat treatment:
- Solution Annealing: 980°C (1800°F) for 1 hour, oil quench or water quench. This dissolves carbides and prepares the matrix for precipitation hardening.
- Aging (Precipitation Hardening): 718°C (1325°F) for 16 hours, air cool. This forms coherent γ' (gamma-prime) precipitates [Ni₃(Al,Ti)] that provide high-temperature strength.
Metallurgical studies show that aging at 730°C accelerates precipitation kinetics but can lead to overaging and formation of η (eta) phase (Ni₃Ti), which degrades mechanical properties. Our controlled aging at 718°C ensures optimal γ' formation while avoiding η phase precipitation, maximizing creep resistance and long-term stability up to 700°C.
Physical Properties of A286
Corrosion Resistance of A286 Button Head Cap Screws
While A286 is primarily selected for high-temperature strength, it also offers good corrosion resistance in many environments due to its high chromium (14-16%) and nickel (24-27%) content. The alloy exhibits excellent oxidation resistance up to 700°C continuous service and 815°C intermittent service.
Oxidation and Scaling Resistance
The chromium content provides excellent resistance to oxidation and scaling. A286 button head cap screws form a protective Cr₂O₃ scale that prevents further oxidation at elevated temperatures. They provide excellent oxidation resistance up to 1500°F (815°C) in conditions typically found in gas turbine exhaust streams.
Corrosion in Other Environments
Critical Corrosion Considerations for Button Head Cap Screws
- Oxidation Resistance: Excellent oxidation resistance up to 1500°F (815°C) in gas turbine and exhaust environments.
- NACE MR0175 Compliance: A286 is qualified for sour service (sulfide stress cracking resistance) in oilfield equipment per NACE MR0175/ISO 15156. Class D with maximum hardness 35 HRC is preferred for sour applications.
- Temperature Limitations: Maximum service temperature for continuous service is 700°C (1300°F). For intermittent service, temperatures up to 815°C are acceptable.
- Galvanic Corrosion: When paired with lower-grade materials, galvanic corrosion should be considered. A286 is cathodic to most stainless steels but compatible with nickel-based alloys.
- Non-Magnetic Property: A286 is essentially non-magnetic, making it suitable for applications requiring non-magnetic fasteners such as MRI equipment and sensitive instrumentation.
- Drive Selection: Hex socket for standard applications, Torx for maximum torque transmission, security Torx for tamper-resistant applications.
High-Temperature Engineering Note: For critical applications in aggressive environments, RAYCHIN LIMITED can provide passivation, specialized coatings (Xylan, PTFE, silver plating per AMS 2410), or recommend optimal heat treatment conditions. Third-party corrosion testing per ASTM G31, G48, or G61 available upon request. NACE MR0175 compliant A286 button head cap screws available in Class D condition with certified hardness ≤ 35 HRC. A286 offers a cost-effective balance of high-temperature strength and corrosion resistance – approximately 60-70% the cost of nickel-based alloys like Inconel 718.
Special focus: A286 Button Head Cap Screws for Aerospace, Power Generation & Oil & Gas
For critical applications requiring low profile and high-temperature strength, RAYCHIN offers A286 button head cap screws manufactured to ASTM, ASME, NACE, and customer-specific specifications. Our capabilities include:
- Aerospace Applications: Gas turbine engines, jet engine nacelles, exhaust systems, thrust reverser mechanisms, control systems, airframe structures, interior cabin components, instrumentation panels. Meets NAS 1351, NAS 1352, MS 16995, MS 16996, MS 16997 specifications.
- Gas Turbines & Power Generation: Turbine casing bolting, combustion chamber supports, heat exchanger connections, steam turbine components, HRSG systems, generator assemblies, instrumentation attachments.
- Oil & Gas: Offshore platform equipment, subsea assemblies, wellhead components, refinery instrumentation, sour service per NACE MR0175, high-temperature control systems.
- Chemical Processing: High-temperature reactor internals, mixer shaft attachments, valve control mechanisms, thermowell assemblies, instrumentation attachments.
- Automotive: Turbocharger components, exhaust manifold attachments, high-performance racing applications, sensor mounting.
- Heat Treating: Fixture assemblies, tray attachments, furnace instrumentation, thermocouple mounting hardware requiring oxidation resistance up to 700°C.
- Aerospace Standards: NAS 1351, NAS 1352, MS 16995, MS 16996, MS 16997
- International Standards: DIN 7380, ISO 7380 (hex socket button head)
- Drive Types: Hex socket, Torx, security Torx, custom drives
- Thread Specifications: UNC/UNF, metric coarse/fine, UNJF-3A per MIL-S-8879, MJ – all classes up to 3A/6g
- Surface Treatments: Silver plating per AMS 2410, passivation per AMS 2700, PTFE coating, Xylan
- Class Selection: Class A (standard strength), Class B, Class D (higher yield strength, API sour service), Cold Worked (maximum strength)
- Custom: Special head diameters, reduced head heights, unusual drive sizes, and custom thread combinations per customer drawings
All A286 button head cap screws are supplied with full traceability and third-party NDT upon request. Sizes available from M2 to M48 (#0 to 2") in all standard configurations. Material certifications (EN 10204 3.1/3.2) included.
Why RAYCHIN LIMITED – The A286 Button Head Cap Screw Authority
Metallurgical competence
Engineers on staff with deep expertise in precipitation hardening superalloys. We ensure proper solution annealing (982°C minimum) and precipitation hardening (718°C for 16 hours) for optimal high-temperature strength and creep resistance across all A286 button head cap screws. Every heat is verified by in-house testing and PMI verification. With 24-27% nickel and titanium-aluminum precipitation hardening, our button head screws provide exceptional strength up to 700°C while maintaining excellent corrosion resistance.
Global approvals & traceability
Our quality system is ISO 9001:2015 and AS9100D certified; we also comply with NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS. Full material traceability from melt to final packaging (EN 10204 3.1/3.2). Third-party inspections (ABS, DNV, Lloyds) available. All A286 button head cap screws meet applicable AMS, ASTM A453, and NACE MR0175 requirements. DIN 7380 and ISO 7380 specifications available.
Precision cold heading & drive forming
In-house precision cold heading and CNC machining ensure consistent head geometry and drive recess formation. Head height controlled to tight tolerances for low-profile applications. Full drive inspection available with optical comparators and go/no-go gauges. Torque testing per IFI standards available. Capability for UNJF-3A threads per MIL-S-8879.
Custom solutions
Need a special head diameter, reduced head height, or custom drive configuration for your high-temperature application? Our cold heading and CNC turning departments handle short runs with agility. We also provide specialized coatings and high-temperature testing per customer requirements. Available in Class A, Class B, Class D (API sour service), and cold worked conditions.
Contact the A286 button head cap screw experts today
Request a quote for A286 button head cap screws, hex socket button head screws, Torx button head screws, low profile button head screws & custom configurations – any global standard (NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS), any quantity. Inquire about high-temperature applications up to 700°C or NACE MR0175 sour service requirements.
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