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A286 Torx Screws

A286 (1.4980) Torx Screws, also known as Alloy 660 Torx Screws are stainless steel alloy which contains iron, nickel and chromium. A286 Torx Screws are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened. As a result, A286 Torx 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 Torx Screws
SKU: 0

Specialist in A286 Torx Screws · Star Drive · Hexalobular · Custom

A286 Torx Screws: High-Temperature Superalloy Star Drive Screws 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 Torx screws — from A286 button head Torx screws, A286 flat head Torx screws, A286 socket head Torx screws to custom non-standard Torx 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 Torx screw applications in gas turbines, exhaust systems, manifold assemblies, power generation, aerospace, and oil & gas (sour service). A286 Torx screws feature a 6-point star-shaped drive pattern (hexalobular per ISO 10664) that provides superior torque transfer and resistance to cam-out compared to Phillips or slotted drives. The Torx drive allows for higher clamping loads without damaging the recess, making these screws ideal for high-vibration and high-temperature environments where reliable fastening is critical. Our portfolio includes Torx 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 Torx screws are supplied in solution annealed and precipitation hardened conditions with full traceability and third-party certifications.

A286 Torx screwsA286 star drive screwsA286 hexalobular screwsA286 button head Torx screwsA286 flat head Torx screwsA286 socket head Torx screwsAlloy 660 Torx screwsUNS S66286 Torx screwsASTM A453 Grade 660 Torx screwsAMS 5732 Torx screwsAMS 5737 Torx screwsNACE MR0175 Torx screwsAPI 20F Torx screws1.4980 Torx screwshigh temperature Torx screwsgas turbine Torx screwsexhaust manifold Torx screwssour service Torx screwscryogenic Torx screws

Complete Range of A286 Torx Screws – Head Styles & Configurations

A286 Button Head Torx Screws

A286 button head Torx screws manufactured to DIN 7380 and ISO 7380 standards with Torx drive. Features a low-profile domed head for smooth appearance and reduced turbulence in fluid applications. The Torx drive provides positive engagement and prevents cam-out during high-torque installation. Ideal for aesthetic applications and where smooth surfaces are required in high-temperature service up to 700°C. Available in sizes from #2 to 3/8" (M2 to M10) in various lengths. Supplied in Class A, B, or D conditions per ASTM A453. Suitable for exhaust systems, heat shields, and turbocharger components.

A286 Flat Head Torx Screws

A286 flat head Torx screws manufactured to DIN 7991 and ISO 10642 standards with Torx drive. Features a countersunk head designed to sit flush with the surface for aerodynamic or aesthetic requirements. The 82° or 90° head angle accommodates standard countersink dimensions. Torx drive allows for higher installation torque without damaging the recess. Ideal for aerospace applications, manifold covers, and equipment where flush mounting is essential. Available with passivated finish per ASTM A967 for enhanced corrosion resistance.

A286 Socket Head Torx Screws

A286 socket head Torx screws combine the high-strength cylindrical head design of socket head cap screws with the superior torque transfer of Torx drive. The combination provides maximum clamping force for critical high-temperature applications. Ideal for gas turbine components, valve assemblies, and high-vibration environments where fastener retention is critical. Available in standard and low head configurations. Precision rolled threads for superior fatigue life and dimensional consistency.

A286 Torx Screws – API & NACE Compliant

A286 Torx 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. Passivated finish available for enhanced corrosion protection.

A286 Tamper-Resistant Torx Screws

A286 tamper-resistant Torx screws feature a modified Torx drive with a center pin that prevents standard Torx bits from engaging. Designed for security applications where unauthorized access must be prevented. Ideal for critical infrastructure, aerospace components, and equipment requiring anti-tamper fasteners in high-temperature environments. Available with various head styles including button, flat, and socket heads. Custom drive configurations available per customer specifications.

Custom & Specialty A286 Torx 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 Torx screws to your drawing. Options include Torx Plus drive, combination drives, shoulder 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 Torx Screws

Superior Torque Transfer

Torx drive provides more points of contact than other drives, allowing higher installation torque without damaging the recess. Resists cam-out and extends tool life.

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 exhaust and turbine applications.

Sour Service Approved

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

Non-Magnetic

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

Oxidation Resistance

Excellent oxidation resistance up to 815°C continuous service and 982°C intermittent. Forms protective Cr₂O₃ scale.

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 Torx Screws

RAYCHIN LIMITED manufactures A286 Torx screws to the following national and international standards, ensuring full compliance for projects worldwide. Both standard and non-standard custom configurations are available.

NASANMSANSIASTMASMESAEAPINACEISODINKSJISGB

Torx Screw Dimensional Standards

Head Style	DIN	ISO	ASME	Drive Standard
Button Head Torx	DIN 7380	ISO 7380	ASME B18.3	ISO 10664 (Torx)
Flat Head Torx	DIN 7991	ISO 10642	ASME B18.3	ISO 10664 (Torx)
Socket Head Torx	—	—	ASME B18.3	ISO 10664 (Torx)
Pan Head Torx	DIN 7985	ISO 7045	ASME B18.6.3	ISO 10664 (Torx)
Tamper-Resistant Torx	—	—	—	Modified Torx with Pin

All dimensional standards available in UNC, UNF, UNJF-3A per MIL-S-8879, and metric thread configurations. Torx drive sizes from T6 to T60 available.

International Standards & Global Designations for A286 Torx Screws

To serve clients worldwide, RAYCHIN LIMITED manufactures A286 Torx 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, ASTM F2281	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 7380/7991 (Torx screws)	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	0Cr15Ni25Ti2MoAlVB · GH2132
Japan (JIS)	JIS G4303, JIS G4311, JIS B1180	SUH 660
ISO	ISO 683-17, ISO 3506-5, ISO 15156-3, ISO 7380, ISO 10642	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 GH2132 SUH660

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

Our A286 Torx 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.

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 Torx Screws (per ASTM A453)

A286 Torx 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

Class D Torx screws are Charpy impact tested at -196°C with 40 J as the minimum qualifying requirement for cryogenic service.

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

A critical requirement for high-temperature Torx 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%

Elevated Temperature Oxidation Resistance

Service Type	Maximum Temperature	Notes
Continuous Service	700°C (1300°F)	High strength retention for sustained operation
Oxidation Resistance (Continuous)	815°C (1500°F)	Excellent scaling resistance
Oxidation Resistance (Intermittent)	982°C (1800°F)	Suitable for short-term exposure

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 Torx screw applications.

Thermal Expansion Properties of A286 Torx Screws

A286 Torx 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 exhaust manifolds and turbine casings.

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
Density	7.92 - 8.14 g/cm³ (0.286 - 0.287 lb/in³)
Melting Point	1370 – 1430°C (2500 – 2610°F)
Modulus of Elasticity	201 - 205 GPa (29,200 - 29,700 ksi)
Magnetic Permeability	≤ 1.01 (non-magnetic)

This expansion match is critical for maintaining clamp load in high-temperature applications where thermal cycling is present. Standard alloy steel fasteners expand less than the surrounding stainless steel components, leading to loss of preload and potential loosening at temperatures above 400°C. A286 eliminates this mismatch.

API 6A & NACE MR0175 Compliance for A286 Torx Screws

A286 Torx 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 Torx 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 Torx Screws

Optimal mechanical properties in A286 Torx 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.

Corrosion Resistance of A286 Torx 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 Torx 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 Torx 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 Torx Screws for High-Temperature & Critical Applications

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

Gas Turbines & Power Generation: Compressor casing fasteners, turbine section assembly, combustion chamber components, exhaust connections, heat shield attachment.
Automotive & Motorsports: Turbocharger fasteners, exhaust manifold screws, header bolts, heat shield attachment, high-performance engine components.
Aerospace: Engine mount fasteners, thrust nozzle assembly, transmission components, missile guidance systems, satellite components. Available with UNJF-3A threads per MIL-S-8879.
Oil & Gas / Sour Service: Wellhead equipment, valve assemblies, subsea connections, refinery piping, NACE MR0175 applications.
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.
Marine Engineering: Non-magnetic components, saltwater-resistant structures, offshore platform equipment.
Head Styles: Button head Torx (DIN 7380/ISO 7380), flat head Torx (DIN 7991/ISO 10642), socket head Torx, pan head Torx, tamper-resistant Torx.
Drive Sizes: T6 through T60 available, custom drive configurations 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, Xylan coatings, PTFE, vacuum-compatible lubricants.
Special Processing: Ultrasonic cleaning, passivation, anti-galling surface treatments.
Class Selection: Class A (standard strength), Class B, Class D (higher yield strength, API sour service), Cold Worked (maximum strength).

All A286 Torx screws are supplied with full traceability and third-party NDT upon request. Sizes available from #0 to 1/2" (M1.6 to M12) in all standard head styles. Material certifications (EN 10204 3.1/3.2) included.

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

Precision Torx drive forming

In-house CNC cold heading and precision drive forming capabilities ensure consistent Torx drive dimensions and superior tool engagement. Precision rolled threads provide excellent fatigue life and dimensional accuracy. 100% drive inspection available. Ultrasonic cleaning and passivation available for critical applications.

Custom solutions

Need a special head style, unusual drive configuration, or custom material certification for your high-temperature application? Our CNC turning and heading departments handle short runs with agility. We also provide specialized coatings, cryogenic impact testing, and NACE MR0175 compliant processing per customer requirements. Available in Class A, Class B, Class D (API sour service), and cold worked conditions.

Contact the A286 Torx screw experts today

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

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