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A286 Socket Head Cap Screws

A286 (1.4980) Socket Head Cap Screws, also known as Alloy 660 Socket Head Cap Screws are stainless steel alloy which contains iron, nickel and chromium. A286 Socket Head Cap Screws are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened. As a result, A286 Socket Head Cap Screws provide high levels of strength from room temperature up to about 1300°F (700°C).

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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

Name: A286 Socket Head Cap Screws
SKU: 0

Specialist in A286 Socket Head Cap Screws · SHCS · Low Head · Button Head · Custom

A286 Socket Head Cap Screws: High-Temperature Superalloy SHCS for Critical Fastening Applications

Precipitation Hardening Iron-Base Superalloy (UNS S66286 / Alloy 660 / 1.4980 / ASTM A453 Grade 660)

RAYCHIN LIMITED is a recognized expert in A286 socket head cap screws — from A286 standard SHCS, A286 low head socket cap screws, A286 button head socket cap screws to custom non-standard socket head cap 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 socket head cap screw applications in gas turbines, vacuum chambers, semiconductor equipment, power generation, aerospace, and oil & gas (sour service). A286 socket head cap screws are specifically designed for applications requiring high strength-to-weight ratio, excellent fatigue resistance, and secure fastening in confined spaces at elevated temperatures. The precision-formed socket provides positive drive and allows for higher clamping loads compared to external drive fasteners. Our portfolio includes socket head cap screws manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards. Engineered for extreme environments where high-temperature strength, creep resistance, and corrosion resistance are critical. A286 socket head cap screws are supplied in solution annealed and precipitation hardened conditions with full traceability and third-party certifications.

A286 socket head cap screwsA286 SHCSA286 socket head cap screwsA286 low head socket cap screwsA286 button head socket cap screwsAlloy 660 socket head cap screwsUNS S66286 socket head cap screwsASTM A453 Grade 660 socket head cap screwsAMS 5732 socket head cap screwsAMS 5737 socket head cap screwsNACE MR0175 socket head cap screwsAPI 20F socket head cap screws1.4980 socket head cap screwshigh temperature SHCSgas turbine SHCSvacuum SHCSsemiconductor SHCSsour service SHCScryogenic SHCS

Complete Range of A286 Socket Head Cap Screws – Head Styles & Configurations

A286 Standard Socket Head Cap Screws

A286 standard socket head cap screws manufactured to ASME B18.3, DIN 912, and ISO 4762 specifications. Features a cylindrical head with a hexagonal socket drive, providing high clamping force and clean appearance. The controlled fillet under the head reduces stress concentration and improves fatigue life. Ideal for high-temperature applications up to 700°C in gas turbines, vacuum chambers, and semiconductor equipment. Available in sizes from #0 to 1" (M1.6 to M24) in various lengths. Supplied in Class A, B, or D conditions per ASTM A453. Precision rolled threads for superior strength and consistency.

A286 Low Head Socket Cap Screws

A286 low head socket cap screws manufactured to ASME B18.3 and DIN 7984 specifications. Features a reduced head height for applications with limited clearance. Maintains the same socket size as standard SHCS for drive tool compatibility. The precipitation-hardened A286 structure ensures exceptional strength at elevated temperatures while maintaining oxidation resistance. Ideal for confined spaces in turbine assemblies, manifold connections, and compact vacuum systems. Available in UNC, UNF, and metric coarse/fine threads.

A286 Button Head Socket Cap Screws

A286 button head socket cap screws manufactured to ASME B18.3 and DIN 7380 specifications. Features a low-profile domed head for smooth appearance and reduced turbulence in fluid applications. The larger head bearing area distributes clamping load evenly. Ideal for aesthetic applications and where smooth surfaces are required. Suitable for high-temperature service up to 700°C in exhaust systems, heat shields, and cryogenic equipment. Available with various point styles and drive options.

A286 Socket Head Cap Screws – API & NACE Compliant

A286 socket head cap screws certified to NACE MR0175 / ISO 15156 for sour service applications in oil and gas industry. Class D condition with controlled hardness ≤ 35 HRC per API 20F BSL2 & BSL3 requirements. Suitable for wellhead equipment, valve assemblies, subsea connections, and refinery applications exposed to H₂S environments. Available in all head styles with 100% hardness testing and Charpy impact testing at -196°C per Class D requirements.

A286 Socket Head Cap Screws for Vacuum & Semiconductor

A286 socket head cap screws specifically designed for vacuum chambers, semiconductor processing equipment, and UHV applications. The alloy's low outgassing characteristics, non-magnetic property, and high-temperature strength make it ideal for these demanding environments. Available with electropolishing for reduced outgassing, ultrasonic cleaning, and Class 100 cleanroom packaging. The venting option (center drilled) eliminates virtual leaks in vacuum systems. Suitable for applications requiring ultimate pressure down to 10⁻⁹ Torr.

Custom & Specialty A286 Socket Head Cap Screws

Need a special head style, unusual drive configuration, or custom length for your high-temperature application? RAYCHIN engineers work with you to produce custom A286 socket head cap screws to your drawing. Options include shoulder screws, fully threaded screws, captive screws, and screws with drilled heads for safety wiring. 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.

Key Benefits of A286 Socket Head Cap Screws

High-Temperature Strength Retention

Maintains high strength up to 700°C, with stress rupture testing at 650°C required per ASTM A453 (386 MPa min for 100 hours). Ideal for turbine and exhaust applications.

Multiple Head Styles Available

Standard SHCS for general use, low head for clearance-limited applications, button head for smooth surfaces. Custom head geometries available.

Sour Service Approved

NACE MR0175 / ISO 15156 qualified for H₂S environments; Class D with hardness ≤ 35 HRC meets API 20F requirements.

Non-Magnetic

Permeability ≤ 1.01, non-magnetic even after severe cold deformation – essential for MRI, particle accelerators, and sensitive instrumentation.

Vacuum Compatibility

Low outgassing characteristics suitable for UHV applications. Ultrasonic cleaning and electropolishing available for critical vacuum service.

Cryogenic Toughness

Maintains ductility and impact strength down to -196°C, with Charpy testing available per Class D requirements (40 J min).

Manufacturing Standards for A286 Socket Head Cap Screws

RAYCHIN LIMITED manufactures A286 socket 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.

NASANMSANSIASTMASMESAEAPINACEISODINKSJISGB

Socket Head Cap Screw Dimensional Standards

Head Style	DIN	ISO	ASME	Military/Aerospace
Standard SHCS	DIN 912	ISO 4762	ASME B18.3	NAS1351, NAS1352, MS16995, MS16996
Low Head SHCS	DIN 7984	ISO 4762 (low head)	ASME B18.3	NAS1353
Button Head SHCS	DIN 7380	ISO 7380	ASME B18.3	MS24667
Flat Head SHCS	DIN 7991	ISO 10642	ASME B18.3	NAS562

All dimensional standards available in UNC, UNF, UNJF-3A per MIL-S-8879, and metric thread configurations. Standard sizes from #0 to 1" (M1.6 to M24).

International Standards & Global Designations for A286 Socket Head Cap Screws

To serve clients worldwide, RAYCHIN LIMITED manufactures A286 socket 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.

Country / Region	Standard / Specification	Designation / Grade
USA	ASTM A453 / A638, ASME SA453, AMS 5731, AMS 5732, AMS 5734, AMS 5737, AMS 5525, AMS 5853, AMS 5858	UNS S66286 · Grade 660 · Alloy 660
Europe (CEN)	EN 10269 (for fasteners), EN 10083-3, EN 10302	1.4980 · 1.4944 · X5NiCrTi26-15 · X6NiCrTiMoVB25-15-2
Germany (DIN)	DIN EN 1.4980, DIN 17440 (former), Werkstoff 1.4980, DIN 912 (SHCS)	1.4980 · X5NiCrTi26-15
France (NF)	NF A35-572/573, NF E25-xxx	Z6NCTDV25-15 · Z5NCTDV26-15B
UK (BS)	BS HR51, BS HR52, BS HR650, BS 2S 143	HR51 / HR52
China (GB)	GB/T 1220, GB/T 20878, GB/T 3098.6, GB/T 70.1 (SHCS)	0Cr15Ni25Ti2MoAlVB · GH2132
Japan (JIS)	JIS G4303, JIS G4311, JIS B1176 (SHCS)	SUH 660
ISO	ISO 683-17, ISO 3506-5, ISO 15156-3, ISO 4762 (SHCS)	X5NiCrTi26-15
NACE	NACE MR0175 / ISO 15156	A286 (qualified for sour service)
API	API 20F, API 6A	Grade 660 Class D (closure bolting)

UNS S66286 Alloy 660 ASTM A453 AMS 5732 AMS 5737 NACE MR0175 1.4980 API 20F

Chemical Composition (Weight %) – A286 Superalloy (UNS S66286 / 1.4980)

Our A286 socket 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.

Element	ASTM A453 / AMS (Range %)	Typical (analysis)
Carbon (C)	≤ 0.08	0.04
Manganese (Mn)	≤ 2.00	1.20
Phosphorus (P)	≤ 0.025	0.015
Sulfur (S)	≤ 0.025	0.010
Silicon (Si)	≤ 1.00	0.50
Chromium (Cr)	13.5 – 16.0	15.0
Nickel (Ni)	24.0 – 27.0	25.5
Molybdenum (Mo)	1.00 – 1.50	1.30
Titanium (Ti)	1.90 – 2.35	2.10
Vanadium (V)	0.10 – 0.50	0.25
Aluminum (Al)	≤ 0.35	0.20
Boron (B)	0.001 – 0.010	0.005
Copper (Cu)	≤ 0.50	0.20
Iron (Fe)	Balance	Balance

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. Boron addition (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 Socket Head Cap Screws (per ASTM A453)

A286 socket 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 unless otherwise noted.

Tensile Requirements by Class – ASTM A453 Grade 660

Class	Size Range	Tensile Strength (min)	Yield Strength 0.2% Offset (min)	Elongation (min)	Reduction of Area (min)
Class A	All sizes	896 MPa (130 ksi)	586 MPa (85 ksi)	15%	18%
Class B	All sizes	793 MPa (115 ksi)	517 MPa (75 ksi)	15%	18%
Class C	All sizes	896 MPa (130 ksi)	586 MPa (85 ksi)	15%	18%
Class D	≤ 2½" (63.5mm)	896 MPa (130 ksi)	724 MPa (105 ksi)	15%	18%
Class D	> 2½" (63.5mm)	825 MPa (120 ksi)	655 MPa (95 ksi)	15%	18%
Cold Worked	All sizes	1103 MPa (160 ksi)	827 MPa (120 ksi)	12%	18%

Hardness Requirements

Class	Brinell Hardness Range	Rockwell C Equivalent
Class A, B, C	248 – 341 HB	24 – 37 HRC
Class D (≤ 2½")	248 – 321 HB	24 – 35 HRC
Class D (> 2½")	248 – 321 HB	24 – 35 HRC
Cold Worked	248 – 341 HB	24 – 37 HRC

For NACE MR0175 / API 20F sour service applications, Class D with maximum hardness 35 HRC is required and 100% hardness testing is mandatory.

Impact Properties (Charpy V-Notch)

Test Temperature	Minimum Average Impact Energy	Notes
-196°C (-320°F)	77 J (57 ft-lbs) typical	Class D requirements: 40 J min at -196°C
-100°C (-148°F)	92 J (68 ft-lbs) typical	API 6A PSL 3/4: 27 J min longitudinal
27°C (80°F)	87 J (64 ft-lbs) typical	Room temperature reference

Stress Rupture Properties (650°C / 1200°F)

A critical requirement for high-temperature socket head cap screws is stress rupture resistance. Per ASTM A453, Class A, B, and C materials must meet the following:

Test Temperature	Applied Stress (min)	Time to Rupture (min)	Elongation (min)
650°C (1200°F)	386 MPa (56 ksi)	100 hours	5%

Note: Class D does not have a stress rupture requirement (marked "NR" in the standard).

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.

Temperature	Yield Strength (typical)	Retention (%)
Room Temperature (20°C)	655 MPa (95 ksi)	100%
200°C (392°F)	620 MPa (90 ksi)	95%
300°C (572°F)	600 MPa (87 ksi)	92%
400°C (752°F)	580 MPa (84 ksi)	89%
500°C (932°F)	550 MPa (80 ksi)	84%
600°C (1112°F)	480 MPa (70 ksi)	73%
650°C (1202°F)	420 MPa (61 ksi)	64%
700°C (1292°F)	350 MPa (51 ksi)	53%

Thermal Expansion Properties of A286 Socket Head Cap Screws

A286 socket head cap screws are designed for applications requiring thermal stability and compatibility with austenitic stainless steel components. The thermal expansion coefficient closely matches that of 304/316 stainless steels, preventing loosening during thermal cycling in high-temperature assemblies such as turbine casings and vacuum chambers.

Property	Value
Thermal Expansion Coefficient (20-100°C)	16.0 – 16.5 x 10⁻⁶ /°C
Thermal Conductivity (20°C)	13 W/m·K
Specific Heat (20°C)	0.42 J/g·°C

API 6A & NACE MR0175 Compliance for A286 Socket Head Cap Screws

A286 socket 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.

Specification	Requirement	A286 Compliance
API 20F BSL2 & BSL3	Maximum hardness 35 HRC	Class D: 24-35 HRC ✓
NACE MR0175 / ISO 15156	Sour service qualification	Qualified for H₂S environments
Charpy Impact @ -196°C	40 J minimum (Class D)	≥ 40 J typical

Application Note: For sour service applications requiring NACE MR0175 compliance, RAYCHIN recommends A286 Class D socket head cap screws with controlled hardness ≤ 35 HRC. 100% hardness testing is performed per API 20F requirements. Suitable for wellhead equipment, valve assemblies, and subsea applications.

Heat Treatment & Microstructural Stability of A286 Socket Head Cap Screws

Optimal mechanical properties in A286 socket head cap screws are achieved through a two-step heat treatment:

Solution Annealing: 982°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 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

Density	7.92 g/cm³ (0.286 lb/in³)
Melting Point	1370 – 1430°C (2500 – 2610°F)
Modulus of Elasticity	201 GPa (29,200 ksi)
Electrical Resistivity	9.1 × 10⁻⁵ ohm-cm
Magnetic Permeability	≤ 1.01 (non-magnetic)

Corrosion Resistance of A286 Socket 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 socket head cap screws form a protective Cr₂O₃ scale that prevents further oxidation at elevated temperatures. They provide excellent oxidation resistance up to 815°C in continuous service and up to 982°C for intermittent service.

Corrosion in Other Environments

Environment	Corrosion Resistance	Notes
Aqueous Corrosion	Good	Similar to 304/316 stainless steels in many environments, with enhanced resistance due to higher nickel content.
Sour Service (H₂S environments)	Good	Qualified per NACE MR0175/ISO 15156 for oil and gas applications.
Chloride Stress Corrosion Cracking	Excellent	The high nickel content (24-27%) provides exceptional resistance to chloride SCC, far superior to 304 and 316 stainless steels.
Oxidizing Acids	Moderate to Good	Suitable for nitric acid applications. Less resistant to reducing acids like hydrochloric.
Cryogenic Temperatures	Excellent	Non-magnetic, excellent for cryogenic equipment down to -196°C.

Critical Corrosion Considerations for Socket Head Cap Screws

Oxidation Resistance: Excellent oxidation resistance up to 815°C in gas turbine and exhaust environments. Suitable for continuous service up to 700°C.
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 (permeability ≤ 1.01), making it suitable for applications requiring non-magnetic fasteners such as MRI equipment and sensitive instrumentation.

Special focus: A286 Socket Head Cap Screws for High-Temperature & Critical Applications

For critical applications requiring high-temperature strength, oxidation resistance, and corrosion resistance, RAYCHIN offers A286 socket head cap screws manufactured to ASTM, ASME, NACE, and customer-specific specifications. Our capabilities include:

Gas Turbines & Power Generation: Compressor casing fastening, turbine section assembly, combustion chamber components, exhaust connections, blade retention.
Vacuum & Semiconductor: Vacuum chambers, UHV systems, semiconductor processing equipment, particle accelerators, mass spectrometers, electron microscopes. Available with venting option for virtual leak elimination.
Oil & Gas / Sour Service: Wellhead equipment, valve assemblies, subsea connections, refinery piping, API 6A closure fastening, NACE MR0175 applications.
Aerospace: Engine mount fasteners, thrust nozzle assembly, transmission components, missile guidance systems, satellite components.
Cryogenic Equipment: LNG facilities, cryogenic storage tanks, superconducting magnets, MRI systems, space simulation chambers.
Chemical Processing: High-temperature reactor fasteners, reformer connections, heat exchanger tube sheets, thermowell assemblies.
Head Styles: Standard SHCS (DIN 912/ISO 4762/ASME B18.3), low head (DIN 7984), button head (DIN 7380), flat head (DIN 7991).
Drive Options: Hex socket (standard), Torx, hexalobular, spline, custom drives per drawing.
Thread Specifications: UNC/UNF, metric coarse/fine, UNJF-3A per MIL-S-8879 – all classes up to 3A/6g.
Surface Treatments: Silver plating per AMS 2410 for anti-seize, passivation per ASTM A967, electropolishing for vacuum service, Xylan coatings, PTFE, vacuum-compatible lubricants.
Special Processing: Ultrasonic cleaning, Class 100 cleanroom packaging, helium leak testing, outgassing testing per ASTM E595.
Class Selection: Class A (standard strength), Class B, Class D (higher yield strength, API sour service), Cold Worked (maximum strength).

All A286 socket head cap screws are supplied with full traceability and third-party NDT upon request. Sizes available from #0 to 1" (M1.6 to M24) in all standard head styles. Material certifications (EN 10204 3.1/3.2) included.

Why RAYCHIN LIMITED – The A286 Socket 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 socket head cap screws. Every heat is verified by in-house testing and PMI verification. With 24-27% nickel and titanium-aluminum precipitation hardening, our SHCS 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 socket head cap screws meet applicable AMS, ASTM A453, and NACE MR0175 requirements.

Precision head forming & threading

In-house CNC turning and precision cold heading capabilities ensure consistent head dimensions and socket geometry. Precision rolled threads provide superior fatigue life and dimensional accuracy. 100% thread inspection available. Ultrasonic cleaning and electropolishing available for critical vacuum and semiconductor applications.

Custom solutions

Need a special head style, unusual drive configuration, or custom material certification for your high-temperature application? Our CNC turning and threading departments handle short runs with agility. We also provide specialized coatings, vented options for vacuum, and cryogenic impact testing per customer requirements. Available in Class A, Class B, Class D (API sour service), and cold worked conditions.

Contact the A286 socket head cap screw experts today

Request a quote for A286 socket head cap screws, standard SHCS, low head, button head & custom configurations – any global standard (NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS), any quantity. Inquire about high-temperature SHCS up to 700°C, vacuum service, NACE MR0175 sour service requirements, or cryogenic applications.

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