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Inconel Hex Cap Screws

Inconel Hex Cap Screws like Inconel 600, 601, 625, 686, 718, 725 & X750 fasteners- bolts, nuts, screws, washers, are a family of nickel-chromium-molybdenum alloys used for their high strength at elevated temperatures and good corrosion resistance. Because of its high thermal stability, Inconel can be used in service temperatures ranging from cryogenic to 2200°F (982°C). The high alloy content of Inconel Nutsenable it to withstand a wide variety of severe corrosive environments. In mild environments, such as the atmosphere, sea water, neutral salts, and alkaline media, there is almost no attack to Inconel Hex Cap Screws. In more severe corrosive environments the combination of nickel and chromium provides resistance to oxidizing chemicals, whereas the high nickel and molybdenum contents supply resistance to nonoxidizing environments.

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A Ni-Cr alloy known for its high temperature stability & corrosion resistance
High temperature stability up to 2200°F (1204°C)
Good corrosion resistance at elevated temperatures
High strength material with excellent toughness at elevated temperatures
Inconel grades: 600, 601, 625, 686, 718, 725, X750

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RAYCHIN LIMITED

Name: Inconel Hex Cap Screws
SKU: 0

Inconel Hex Cap Screws · Hex Head Bolts

Inconel Hex Cap Screws: Nickel-Chromium Superalloy Hex Head Bolts for Extreme Environments

Inconel 600 (UNS N06600 / 2.4816) | 625 (UNS N06625 / 2.4856) | 718 (UNS N07718 / 2.4668) | X-750 (UNS N07750) | 601 (UNS N06601 / 2.4851)

RAYCHIN LIMITED is a leading manufacturer of Inconel Hex Cap Screws – precision hex head bolts designed for high-strength fastening in critical assemblies. These Inconel hex head cap screws are available in both heavy hex and finished hex patterns, with full or partial thread options, and conform to ASME B18.2.1, DIN 931/933, and ISO 4014/4017 standards. Manufactured from premium nickel‑chromium superalloys, they deliver exceptional high‑temperature strength up to 1150°C, outstanding oxidation resistance, and immunity to chloride‑ion stress corrosion cracking. Our portfolio includes all standard and custom configurations manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards. Whether you require Inconel 718 hex cap screws for aerospace turbine assemblies, Inconel 625 hex head bolts for offshore platforms, or Inconel 600 hex cap screws for nuclear applications, RAYCHIN delivers precision, quality, and full traceability. All mechanical properties are presented in MPa and ksi (kilopound per square inch).

Inconel hex cap screwsInconel hex head boltsInconel 600 hex cap screwsInconel 625 hex cap screwsInconel 718 hex cap screwsInconel X-750 hex head boltsUNS N06600 hex cap screwsUNS N06625 hex cap screwsUNS N07718 hex cap screws2.4816 hex head bolts2.4856 hex cap screws2.4668 hex cap screwsASTM B166 hex cap screwsASTM B446 hex cap screwsASTM B637 hex cap screwsASME SB166 hex head boltsNACE MR0175 hex cap screwshigh temperature hex head boltscorrosion resistant hex cap screwsaerospace hex boltsDIN 931 Inconel hex boltsISO 4014 Inconel hex bolts

Inconel Hex Cap Screws – Types & Configurations

Heavy Hex & Finished Hex

Inconel heavy hex cap screws feature a larger hex head for higher wrenching torque, ideal for pressure vessels and flanged connections. Inconel finished hex bolts (regular hex) are used in general assembly. Available in sizes #10 to 4" (M5 to M100) with UNC, UNF, and metric coarse threads. Head markings optional per customer specification.

Thread Configurations

Inconel hex cap screws supplied in full thread (tap-end) and partial thread (body diameter) styles. Thread classes 2A, 3A, UNJF-3A, 6g. Lengths from 1/2" to 20" (12mm to 1000mm). Precision rolled threads for superior fatigue life and consistent fit. Custom thread lengths and diameters available.

Aerospace & Military Standards

Our Inconel hex head cap screws meet NAS1802 (hex head), MS16995 (reduced head), AN3 through AN20 (aircraft bolts), and MS20073 through MS20083. Full compliance with AMS 5662 (718), AMS 5666 (625), AMS 5665 (600), and AMS 5667 (X-750) for material and heat treatment.

Industrial & Petrochemical Grades

Inconel hex cap screws for oil & gas, chemical processing, and power generation manufactured to ASTM B166 (600/601), ASTM B446 (625), ASTM B637 (718/X-750), API 20F, and NACE MR0175/ISO 15156. Supplied with EN 10204 3.1/3.2 certifications and full NDT (PMI, UT, MPI) upon request.

Surface Finish Options

Passivated per ASTM A967, silver plating per AMS 2410 (anti‑seize for high‑temperature), PTFE coating for anti‑galling, electropolished for clean room applications, and zinc‑nickel plating for additional corrosion resistance. Custom finishes available.

Custom & Non-Standard Hex Cap Screws

Need a special head height, extra-long length, or proprietary head markings? RAYCHIN engineers design and produce custom Inconel hex cap screws to your exact specifications – any Inconel grade, any heat treat condition (annealed, aged), with full material traceability. Prototype to production volumes supported.

Critical Applications of Inconel Hex Cap Screws

Aerospace & Defense

Inconel 718 hex cap screws used in turbine engine casings, landing gear attachments, flight control systems, and rocket motor components. Withstand 650°C operating temperatures and extreme vibration. Tensile strength up to 1270 MPa ensures structural integrity under high-G maneuvers.

Oil & Gas / Sour Service

Inconel 625 hex cap screws and Inconel 718 hex head bolts qualified per NACE MR0175 for wellhead equipment, valve bonnets, and subsea actuators. Resist sulfide stress cracking (SSC) and pitting in H₂S/CO₂ environments at elevated pressures and temperatures.

Power Generation

Inconel hex cap screws in gas turbines, steam turbines, and nuclear reactors provide reliable joining of casings, flanges, and support structures. Maintain clamping force after thousands of thermal cycles from -200°C to 700°C without relaxation. Inconel 600 offers excellent performance in nuclear service.

Chemical Processing

Inconel 625 hex cap screws resist boiling sulfuric acid, hydrochloric acid, and chlorinated solvents in reactor agitators, pump shafts, and valve assemblies. Immunity to chloride stress corrosion cracking ensures long-term reliability in aggressive media.

Marine & Offshore

Inconel hex cap screws in seawater pump couplings, propeller shaft locking devices, and subsea control modules resist pitting and crevice corrosion in saltwater. Zero fastener failures reported after 3+ years continuous offshore operation.

Industrial Heat Treatment

Inconel 601 hex cap screws used in furnace fixtures, radiant tubes, and conveyor belts. Superior cyclic oxidation resistance up to 1150°C ensures long service life in air and carburizing atmospheres.

International Standards & Global Designations – Inconel Hex Cap Screws

RAYCHIN LIMITED manufactures Inconel hex cap screws from material conforming to the most widely used national and international specifications. All material is traceable to the mill.

Inconel Grade	UNS	DIN / W. Nr.	EN	BS	Applicable Specifications (Hex Cap Screws)
Inconel 600	N06600	2.4816	NiCr15Fe	NA14	ASTM B166 / ASME SB166; AMS 5665; NACE MR0175; DIN 931/933
Inconel 625	N06625	2.4856	NiCr22Mo9Nb	NA21	ASTM B446 / ASME SB446; AMS 5666; API 6A; NACE MR0175; ISO 4014
Inconel 718	N07718	2.4668	NiCr19Fe19Nb5Mo3	—	ASTM B637; AMS 5662 / 5663; API 6A718; NACE MR0175 / ISO 15156‑3
Inconel X-750	N07750	2.4669	NiCr15Fe7TiAl	—	ASTM B637; AMS 5667 / 5668; NACE MR0175
Inconel 601	N06601	2.4851	NiCr23Fe	—	ASTM B166 / ASME SB166; AMS 5870; superior oxidation resistance up to 1150°C

UNS N06600 2.4816 UNS N06625 2.4856 UNS N07718 2.4668 UNS N07750 2.4669 NACE MR0175 API 20F

Chemical Composition (Weight %) – Inconel Alloys for Hex Cap Screws

Our Inconel hex cap screws are produced from melts conforming to the following limits per ASTM/ASME/AMS.

Inconel 600 (UNS N06600 / 2.4816)

Element	Min %	Max %	Typical
Ni (+Co)	72.0	—	76.0
Cr	14.0	17.0	15.5
Fe	6.0	10.0	8.0
C	—	0.15	0.08
Mn	—	1.0	0.5
Si	—	0.5	0.2
S	—	0.015	0.008
Cu	—	0.5	0.2

Inconel 625 (UNS N06625 / 2.4856)

Element	Min %	Max %	Typical
Ni (+Co)	58.0	—	61.0
Cr	20.0	23.0	21.5
Mo	8.0	10.0	9.0
Nb (+Ta)	3.15	4.15	3.6
Fe	—	5.0	2.5
C	—	0.10	0.03
Mn	—	0.50	0.2
Si	—	0.50	0.2
Al	—	0.40	0.2
Ti	—	0.40	0.2

Inconel 718 (UNS N07718 / 2.4668)

Element	Min %	Max %
Ni	50.0	55.0
Cr	17.0	21.0
Nb (+Ta)	4.75	5.50
Mo	2.80	3.30
Ti	0.65	1.15
Al	0.20	0.80
Fe	balance
Mn	—	0.35
Si	—	0.35
C	—	0.08
S	—	0.015
P	—	0.015
B	—	0.006
Cu	—	0.30

Metallurgical note: High nickel content (≥50%) provides exceptional resistance to chloride stress corrosion cracking. Chromium (14–23%) ensures oxidation resistance up to 1150°C. Molybdenum (in 625) and Nb+Ti (in 718/X-750) contribute to solid‑solution strengthening and precipitation hardening, giving these Inconel hex cap screws their signature high‑temperature strength and corrosion resistance.

Complete Mechanical & Physical Properties – Inconel Hex Cap Screws (MPa / ksi)

Inconel hex cap screws are supplied in solution annealed (600, 625, 601) or age‑hardened (718, X‑750) condition per specification. Data represent typical values based on ASTM, AMS, and industry standards. ksi values (kilopound per square inch) are provided alongside MPa.

Mechanical Properties – Typical Values (room temperature) for Hex Cap Screws

Grade / Condition	Tensile Strength (MPa)	Tensile Strength (ksi)	Yield Strength 0.2% (MPa)	Yield Strength 0.2% (ksi)	Elongation (%)	Hardness
Inconel 600 (annealed)	550-695	79.8-100.8	205-352	29.7-51.0	35-55	65-85 HRB
Inconel 625 (annealed)	827-930	120.0-135.0	414-517	60.0-75.0	30-42	≤95 HRB
Inconel 718 (age hardened)	1240-1455	179.8-211.0	1035-1180	150.1-171.1	12-21	36-44 HRC
Inconel X-750 (aged)	1170-1170	169.7-169.7	760-790	110.2-114.6	10-15	30-38 HRC
Inconel 601 (annealed)	550-550	79.8-79.8	240-240	34.8-34.8	30-30	≤88 HRB

Physical Properties (typical) – Inconel Hex Cap Screws

Property	Inconel 600	Inconel 625	Inconel 718	Inconel 601
Density (g/cm³)	8.42-8.47	8.44	8.19-8.24	8.11
Melting Range (°C)	1355-1425	1290-1350	1260-1344	1320-1370
Thermal Conductivity (W/m·K) at 20°C	14.9-16.7	9.8	11.4	11.2
Modulus of Elasticity (GPa)	207-214	205	200-205	207

High‑Temperature Performance of Inconel Hex Cap Screws

Inconel superalloys retain significant strength at elevated temperatures, making Inconel hex cap screws ideal for gas turbines, furnace assemblies, and exhaust systems. Data below demonstrate the superiority of Inconel 718, 625, and 601 for high‑T applications.

Elevated Temperature Strength – Comparison by Grade

Grade	Maximum Service Temperature (oxidizing)	Tensile Strength at 650°C (MPa)	Tensile Strength at 650°C (ksi)	Characteristics
Inconel 600	1095°C (2000°F)	~250	~36.3	Good oxidation resistance; retains ~45% of RT strength at 650°C
Inconel 625	980°C (1800°F)	~415	~60.2	Excellent strength up to 980°C; resists creep
Inconel 718	700°C (1300°F)	1160	168.2	Highest strength up to 700°C; retains 80% of RT strength at 650°C
Inconel 601	1150°C (2100°F)	~210	~30.5	Superior cyclic oxidation resistance due to aluminum addition

At 650°C, Inconel 718 retains about 80% of its room‑temperature tensile strength, outperforming many other alloys. Inconel 625 and 601 provide outstanding resistance to oxidation and carburization at even higher temperatures, making them excellent choices for high‑temperature hex cap screws.

High‑Temperature Limits & Oxidation Resistance

Grade	Maximum Service Temperature (oxidizing)	Characteristics
Inconel 600	1095°C (2000°F)	High strength at 650°C; highest operating temperature in air is 1175°C
Inconel 625	980°C (1800°F)	Good tensile and fatigue properties below 980°C; resists creep
Inconel 718	700°C (1300°F)	High tensile and fatigue strength at 700°C; high oxidation resistance at 1000°C
Inconel 601	1150°C (2100°F)	Superior cyclic oxidation resistance due to aluminum addition; ideal for furnace fixtures

Exceptional Corrosion Resistance of Inconel Hex Cap Screws

The high nickel and chromium content imparts resistance to a wide range of corrosive media: chlorides, acids, and alkalis. Inconel 625 and Inconel 718 hex cap screws are particularly resistant to pitting and crevice corrosion in seawater and sour environments.

Chloride stress corrosion cracking (SCC): All Inconel grades exhibit high resistance due to Ni >40%; immune to chloride-ion SCC.
Sulfuric & Hydrochloric acids: Inconel 625 shows exceptional performance in reducing acids (Mo addition).
Sour service (H₂S): Inconel 625 & 718 qualified per NACE MR0175/ISO 15156 for oil & gas.
Oxidation & carburization: Inconel 601 outperforms due to aluminum addition.
Seawater: Inconel 625 resists pitting and crevice corrosion, used extensively in marine fasteners.
High-purity water & alkalis: Inconel 600 offers excellent corrosion resistance in nuclear applications.
Ammonia: Inconel 600 demonstrates almost total corrosion resistance to ammonia.

Manufacturing Standards – Inconel Hex Cap Screws

All Inconel hex cap screws are manufactured and tested to meet:

NAS (NAS1802)MS (MS16995, MS20073-20083)AN (AN3-AN20)ANSI B18.2.1, B18.2.3.6MASTM B166, B446, B637ASME SB166, SB446SAE (AMS 5662, 5663, 5666, 5665, 5667)API 6A, 20FNACE MR0175 / ISO 15156ISO 4014, 4017, 4018DIN 931, 933, 558KS B1002, B1003

We offer surface finishes: passivation (ASTM A967), silver plating (AMS 2410 for anti‑seize), PTFE coating, electropolish, and zinc‑nickel plating. Full traceability and destructive/non‑destructive testing available (UT, MPI, PMI).

Why RAYCHIN LIMITED – The Inconel Hex Cap Screw Authority

Metallurgical expertise: Decades of experience with nickel superalloys. We ensure correct heat treatment: solution anneal for 600/625/601, age hardening for 718/X‑750 per AMS/ASTM schedules. In‑house PMI verifies chemistry of every heat.

Global certifications: ISO 9001, AS9100D, PED, API Q1. All hex cap screws supplied with EN 10204 3.1/3.2 certifications, NACE compliance when required.

Precision forming & threading: CNC cold heading and thread rolling ensure consistent head geometry, accurate hex dimensions, and Class 2A/3A thread fit. 100% inspection available.

Custom solutions: Special head markings, non‑standard lengths, proprietary drive options, and tailored packaging. We support urgent delivery and JIT programs.

Contact the Inconel hex cap screw experts

Request a quotation for Inconel hex cap screws, hex head bolts, heavy hex cap screws – any standard (NAS, MS, AN, ANSI, ASTM, ASME, API, NACE, ISO, DIN, KS) – any Inconel grade, any quantity. Global delivery. Mechanical data in MPa/ksi available for all products.

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