Inconel 718 Heavy Hex Nuts
ASME B18.2.2ASTM B637
Inconel 718 heavy hex nuts pair a precipitation-hardened nickel-chromium alloy with a larger bearing face for high-load turbine and steam bolt systems. Paired with matching 718 bolts and studs, they distribute bearing load and support full thread engagement.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Solution treated / solution treated and aged
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Finished-Nut Specifications
Threads · Metric
Threads · Inch
Dimension Reference
Heat Treatment
Solution treated and agedFor A1014 bolting, solution treatment is followed by precipitation aging to develop the specified high-temperature strength.
What we can make in Alloy 718
Regular hex
Use on equipment covers and mounting brackets with standard socket access. The compact wrenching envelope is useful where adjacent fasteners or housing walls restrict tool clearance.
Heavy hex
Use on flange-bolting sets and pressure-equipment joints calling for a heavy-hex pattern. The wider bearing footprint and larger wrench size require more seat area and socket clearance than a regular hex nut.
Thin hex
Use in restricted axial spaces or as part of a specified two-nut locking arrangement. Reduced thread engagement means a thin nut is not a direct load-capacity replacement for a full-height nut.
- Metric thread
- M4–M100
- Inch thread
- 1/4″–4″
- Patterns
- Heavy hex
- Thread systems
- Metric · UNC · UNF · 8UN · UNJ
- Final condition
- Solution treated · solution treated and aged
- Inspection
- Thread plug gauges · Across flats · Nut height
Manufacturing route
Small lots use machined blanks. Volume nut blanks use a forming route compatible with the alloy before machining the bore and tapping.
Heat treatment & final condition
Solution treatment and the specified aging condition are recorded against the production lot; final dimensions are checked after thermal processing.
Finished geometry
Internal thread gauging, usable engagement and bearing-face alignment are checked after final processing.
Where 718 fits — and what matters
Gas & steam turbine casing joints
Inconel 718 Heavy Hex NutsA high-strength turbine casing stud needs a nut whose proof load suits the stud, as well as enough bearing area on the casing. Inconel 718 heavy hex nuts provide a substantial nut pattern in a precipitation-hardened alloy. Their wider flats also support robust socket engagement during controlled assembly.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Temperature range, cycling duty, and age-hardened condition certification
Generator & rotor tie-bolt assemblies
Inconel 718 Heavy Hex NutsRotor tie-bolt nuts transfer a large axial load into the end of the assembly. A heavy hex 718 nut offers a strong threaded section and a generous bearing footprint where the rotor design allows it. The drawing's balance, seating and locking details remain essential parts of this particular component.
Connection requirements
- Mating tie-bolt diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Load, cycling duty, and age-hardened condition certification
High-pressure steam valve bonnets
Inconel 718 Heavy Hex NutsSteam-valve bonnet nuts carry the stud load above the pressure cover. Inconel 718 heavy hex nuts suit assemblies specifying high-strength hot-service bolting, with the nut heat treatment and proof load matched to the stud. The larger pattern is helpful where the bonnet spotface provides adequate bearing space.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Temperature range, cycling duty, and age-hardened condition certification
Same heavy hex nut. Different material priorities.
Inconel 718 material dataA-286 Heavy Hex Nuts
A-286 heavy hex nuts carry hot casing, bonnet and tie-bolt loads through a broad bearing face. The precipitation-hardened iron-nickel alloy supplies elevated-temperature strength, while the heavy pattern fits substantial cover spotfaces. Large flats give a socket useful engagement when the assembly is tightened or opened for overhaul.
Inconel X-750 Heavy Hex Nuts
On a hot casing or valve cover, Inconel X-750 heavy hex nuts transfer sustained stud loads into a substantial seating face. Their precipitation-treated condition supplies hot-strength properties, and the heavy pattern adds wrench engagement for assembly tooling. Nut condition and proof load are paired with the mating stud's requirements.
Inconel 625 Heavy Hex Nuts
Inconel 625 heavy hex nuts suit substantial seawater and wet-chloride stud connections. Localized-corrosion resistance matters beneath the seating face and inside the loaded threads. The broad pattern fits robust pump spotfaces and subsea connections with sufficient clearance for the installation tooling.
From drawing to documented delivery
- 01Drawing & BOMForm, dimensions and quantity
- 02Material & formingGrade, heat and manufacturing route
- 03Final inspectionGeometry, threads and ordered tests
- 04Documents & dispatchLot records and identified packing
Order documents
- Material identity
- UNS N07718 · heat number · ordered condition
- Final-part acceptance
- Lot-linked aging record and mechanical acceptance in the final condition.
- Dimensional record
- Thread plug gauges · Across flats · Nut height
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your 718 heavy hex nut enquiry
Questions about 718 hex nuts
Does a matching UNS make the stud and nut a matched set?
Matching chemistry addresses only one part of the order. Nut strength, effective engagement, internal thread fit and surface friction must also suit the stud and assembly tightening method.