Nickel Alloy Fasteners for Corrosive and High-Temperature Service
Specify bolts, screws, nuts, studs, threaded rods and washers by alloy, dimensional standard, thread system, material condition and inspection requirement.
Fastener Types Available for Review
Bolts and Cap Screws
Hex bolts, heavy hex bolts, square-head bolts, T-head bolts, U-bolts, eye bolts, socket head cap screws and countersunk screws.
Studs and Threaded Rods
Continuous-thread studs, double-end studs, tap-end studs, flange bolting studs and drawing-based threaded rods.
Nuts
Hex nuts, heavy hex nuts, thin nuts, jam nuts, coupling nuts and 6- or 12-point flange nuts where the design is feasible.
Washers and Special Parts
Plain washers, spring washers, square washers, spacers, retainers and custom-machined fastening components.
The descriptions above identify quotation categories, not guaranteed stock. Supply depends on grade, dimensions, thread, condition, quantity, testing and drawing requirements.
Nickel Alloy Fastener Material Selection
| Material | Why It Is Considered | Typical Starting Applications | Selection Note |
|---|---|---|---|
| Inconel 718 UNS N07718 | High strength after precipitation hardening; good elevated-temperature capability | Aerospace, turbines, high-load studs and bolts | Confirm heat treatment, section size, strength class and governing specification |
| A286 / Grade 660 UNS S66286 | High-temperature strength with oxidation resistance | Valve, flange, turbine and pressure-equipment bolting | ASTM A453/A453M Grade 660 may apply when specified by the design |
| Inconel X-750 UNS N07750 | Precipitation-hardenable; spring and elevated-temperature performance | Spring washers, bolts and hot fastening components | Specify product form, condition and required mechanical properties |
| Inconel 625 UNS N06625 | Strong chloride, seawater and general corrosion resistance | Marine, offshore, chemical processing and pollution control | Choose when corrosion resistance is more important than maximum precipitation-hardened strength |
| Hastelloy C-276 UNS N10276 | Resistance to many severe reducing and oxidizing chemical environments | Acid processing, reactors, scrubbers and aggressive chemical service | Review medium, concentration, temperature and crevice conditions |
| Monel 400 UNS N04400 | Nickel-copper corrosion resistance, especially in selected marine and chemical media | Marine hardware, pumps, valves and process equipment | Confirm compatibility with the actual medium and galvanic couple |
| Nickel 200 / Nickel 201 | Commercially pure nickel for caustic service and conductivity | Alkali processing and special electrical/chemical equipment | Nickel 201 is the lower-carbon choice commonly considered for higher-temperature service |
| 17-4PH and 2507 | High-strength stainless alternatives for suitable environments | Valves, pumps, marine and chloride service where approved | These are not nickel alloys; compare corrosion limits, strength, cost and project code |
Material selection must be confirmed by the project engineer against the design code, load, temperature, service medium, corrosion mode, mating materials and maintenance strategy.
Fastener Size, Thread and Manufacturing Options
Typical RFQ Range
- Inch nominal diameter: approximately 1/4 to 4 in.
- Metric nominal diameter: approximately M4 to M100
- UNC, UNF, UNJ, metric coarse or fine threads as specified
- Standard lengths or custom dimensions to drawing
- Cold formed, hot formed or machined routes subject to alloy and size
Engineering Details to Confirm
- Rolled versus cut threads and the stage of heat treatment
- Full or partial thread, grip length and thread engagement
- Head style, wrench size, shank, under-head radius and runout
- Nut pairing, proof/load requirements and galling control
- Surface finish, cleaning, passivation or project-approved coating
Torque values are not universal material properties. Joint design, lubrication, coating, thread fit, reuse policy and target preload must be established by the responsible engineer.
ASTM, ASME, ISO and Drawing Standards
| Purpose | Common Reference | How to Use It |
|---|---|---|
| Material and mechanical requirements | ASTM F468/F468M | Nonferrous bolts, hex cap screws, socket head cap screws and studs for general use; verify the alloy and current edition |
| Material and mechanical requirements | ASTM F467/F467M | Nonferrous nuts for general use |
| Heat-resistant bolting | ASTM F2281 | Stainless steel and nickel alloy bolts, cap screws and studs for heat resistance and high-temperature applications |
| High-temperature bolting | ASTM A453/A453M | Includes Grade 660 bolting material used for high-temperature pressure equipment and valve/flange applications |
| Inch dimensions | ASME B18 series | B18.2.1 bolts and screws, B18.2.2 nuts, B18.3 socket products, B18.21.1 washers and B18.31.2 studs |
| Metric dimensions | ISO 4014, ISO 4017, ISO 4032 | Common dimensional references for metric hex bolts, screws and nuts; material and mechanical requirements must be stated separately |
| Customer/project requirements | DIN, ANSI, GB, BS or drawing-based | Confirm edition, dimensions, tolerances, thread system, alloy, condition, testing and acceptance criteria |
Always state the required standard edition in the purchase order. A dimensional standard does not by itself define nickel alloy chemistry, heat treatment, mechanical properties or inspection.
European Standards and PED Documentation
European fastener enquiries normally need three separate layers to be defined: the nickel alloy material and delivery condition, the EN ISO dimensional and thread requirements, and the inspection or pressure-equipment documentation route. The references below are starting points; the responsible equipment manufacturer or project engineer must confirm applicability.
| Purpose | European Reference | How to Specify It |
|---|---|---|
| Fastener material for elevated or low temperature | EN 10269 / DIN EN 10269 | Specifies steels and nickel alloys supplied as semi-finished products, bars and rods for fasteners with specified elevated- and/or low-temperature properties. Confirm that the selected grade, delivery condition and finished-product requirements cover the project. |
| Inspection documents | EN 10204 Type 2.2, 3.1 or 3.2 | State the required inspection document type in the purchase order. Type 3.1 is commonly requested; Type 3.2 requires validation by the purchaser or designated inspection representative as defined by the standard. |
| Metric bolt, screw and nut dimensions | EN ISO 4014, EN ISO 4017, EN ISO 4032 and EN ISO 4762 | Dimensional references for hex bolts, screws, nuts and socket head cap screws. They do not independently define nickel alloy chemistry, heat treatment or mechanical properties. |
| Metric threads and washers | EN ISO 261 / EN ISO 965 and EN ISO 7089 / 7090 | Use the thread series and tolerance standards together with the applicable washer dimensions. State thread tolerance, fit and any coating allowance explicitly. |
| PN-designated flange bolting | EN 1515-1 / EN 1515-2 | Used for selection and classification of bolting materials for PN-designated flanges. Confirm the flange system, pressure-temperature conditions, material pairing and applicable part/edition. |
| European pressure-equipment projects | Pressure Equipment Directive 2014/68/EU (PED) | State the equipment category, material approval route, Particular Material Appraisal requirements where applicable, notified-body involvement, traceability and inspection-document requirements. The equipment manufacturer remains responsible for conformity assessment. |
| Legacy DIN drawing references | DIN 931, DIN 933 and DIN 934 | These designations still appear on customer drawings. Confirm the edition and permitted EN ISO substitution instead of silently converting dimensions or tolerances. |
EN ISO 3506 applies to corrosion-resistant stainless steel fasteners and ISO 898 applies to carbon and alloy steel fastener property classes. They should not be used as substitute nickel alloy material specifications for Inconel, Hastelloy, Monel or commercially pure nickel fasteners.
European Project RFQ Checklist
Material and Geometry
- Nickel alloy grade, UNS number and EN or Werkstoff designation where applicable
- EN 10269 grade, delivery condition and mechanical-property requirements when specified
- EN ISO dimensional standard or controlled drawing, including revision
- Metric thread series, pitch, tolerance class, fit and coating allowance
- Fastener type, nominal diameter, length, grip and quantity
Documentation and Project Approval
- Required EN 10204 document type: 2.2, 3.1 or 3.2
- PED category and material route, including PMA where required
- Notified-body or third-party inspection and witness points
- PMI, mechanical testing, NDE, marking and full heat/lot traceability
- EN 1515 and flange-system requirements for pressure-joint bolting
Do not request “PED compliant fasteners” without identifying the equipment category, design code and conformity-assessment route. These inputs determine the documentation and approval scope.
Choose Fastener Materials by Industry
| Industry | Common Starting Materials | Components | Critical Inputs |
|---|---|---|---|
| Aerospace | Inconel 718, X-750, A286 | Engine mounts, turbine hardware, hot fasteners and high-load components | Strength at temperature, fatigue, heat treatment and traceability |
| Oil & Gas / Sour Service | Inconel 625, 718, 725; super duplex alternatives | Wellhead, subsea, valve and flange bolting | Project/API/NACE requirements, preload, corrosion and hydrogen-related risks |
| Marine & Offshore | Inconel 625, Monel 400, 2507 alternatives | Pumps, valves, flanges, deck and submerged equipment | Chlorides, crevices, galvanic compatibility and seawater velocity |
| Chemical Processing | Hastelloy C-276/C-22, Inconel 625, Nickel 200/201 | Reactors, piping, scrubbers and acid/alkali systems | Medium, concentration, contamination, temperature and cleaning cycle |
| Power Generation | Inconel 718, X-750, A286 | Turbines, exhaust systems, heat shields and pressure joints | Creep, oxidation, thermal cycling and joint relaxation |
| Industrial Furnaces | X-750, A286 and heat-resistant nickel alloys | Fixtures, retainers and hot-zone fastening | Oxidation, carburization, thermal expansion and maintenance cycle |
Quality, Inspection and Traceability
Common Documentation
- EN 10204 3.1 material test certificate where requested
- Heat and lot traceability from raw material to finished fastener
- Chemical composition and mechanical test results
- Heat-treatment records and hardness results where applicable
- Dimensional and thread-gauge inspection report
Optional Project Inspection
- Positive material identification (PMI)
- Tensile, wedge or axial testing as required by specification
- Dye penetrant, ultrasonic or other NDE when applicable
- Surface, marking, cleanliness and packaging inspection
- Third-party witness or inspection to an agreed ITP
Related Material and Application Pages
Nickel Alloy Fastener FAQ
Which nickel alloy fastener is best for high-temperature service?
There is no universal best grade. Inconel 718 is a common starting point where high strength and elevated-temperature performance are required; Inconel X-750 is often considered for hot springs and fastening components; A286 is widely specified for high-temperature bolting. The service temperature, load, oxidation, corrosion, heat treatment and governing specification must be reviewed together.
What is the difference between Inconel 718 and Inconel 625 fasteners?
Inconel 718 is normally selected when precipitation-hardened strength is the main requirement. Inconel 625 is commonly selected when corrosion resistance, chloride resistance and fabrication performance are more important than the highest fastener strength. Final selection depends on the design code and service conditions.
Which standards apply to nickel alloy bolts, nuts and studs?
ASTM F468/F468M and F467/F467M are common general-use material references for nonferrous externally and internally threaded fasteners. ASTM F2281 covers heat-resistant stainless steel and nickel alloy bolts, cap screws and studs. European projects may also reference EN 10269 for elevated- or low-temperature fastener materials, EN ISO dimensional standards and EN 10204 inspection documents. The purchase order must identify the required alloy, dimensions, mechanical properties, heat treatment, testing and standard edition.
Can nickel alloy fasteners be supplied to EN 10269 and PED requirements?
They can be reviewed for European projects when the required alloy grade, product form, material condition, mechanical properties, EN 10204 document type and project approval route are defined. EN 10269 supports material specification for fasteners used at elevated or low temperatures, but citing EN 10269 alone does not automatically make a finished fastener or pressure-equipment assembly compliant with PED 2014/68/EU. State the PED category, harmonized-material route or Particular Material Appraisal requirement, notified-body involvement and traceability requirements in the enquiry.
What nickel alloy fastener sizes can be quoted?
A practical enquiry range is approximately 1/4 to 4 inches or M4 to M100, including drawing-based sizes. Availability depends on the alloy, fastener type, thread, quantity, manufacturing route, heat treatment and inspection requirements, so the range is not a stock guarantee.
Can nickel alloy fasteners be manufactured to a drawing?
Yes, drawing-based bolts, studs, nuts, washers and machined fasteners can be reviewed. The drawing should state dimensions, tolerances, thread system, alloy, material condition, surface requirements, inspection characteristics and acceptance criteria.
What information is needed for a nickel alloy fastener RFQ?
Provide the fastener type, alloy and UNS number, dimensional standard or drawing, diameter, thread pitch, length, quantity, heat treatment or condition, mechanical requirements, inspection scope, certification, destination and required delivery time.
Request a Nickel Alloy Fastener Quote
Send enough information to identify both the component geometry and the required material performance. For a drawing-based item, attach a controlled drawing and state the inspection characteristics.
- Fastener type, alloy/UNS number and quantity
- Dimensional standard or drawing revision
- Diameter, thread system, pitch, length and tolerances
- Material condition, heat treatment and mechanical requirements
- Certification, PMI/NDE, third-party inspection and destination
- For European projects: EN 10269 condition, EN 10204 document type, PED category/material route and notified-body requirements where applicable