Inconel 625 Hex Nuts
ISO 4032ASTM B446
Inconel 625 hex nuts pair a solid-solution nickel-chromium-molybdenum alloy with a standard-height mating nut for seawater, marine, and wet-process bolt systems. Paired with matching 625 bolts and studs, they support full thread engagement within standard height.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Annealed / solution annealed
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
Annealed or solution annealedFor B446 stock, Grade 1 is annealed and Grade 2 is solution annealed; the higher-temperature solution treatment supports creep resistance rather than age hardening.
What we can make in Alloy 625
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
- Regular hex · Heavy hex
- Thread systems
- Metric · UNC · UNF · 8UN · UNJ
- Final condition
- Annealed · solution annealed
- 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
The final annealed or specified strengthened condition is linked to the lot; an aging treatment is not assumed for a solid-solution alloy.
Finished geometry
Internal thread gauging, usable engagement and bearing-face alignment are checked after final processing.
Where 625 fits — and what matters
Subsea & topside piping joints
Inconel 625 Hex NutsRegular hex Inconel 625 nuts suit offshore bracket and piping connections with limited clearance around the studs. Their corrosion resistance protects the internal threads and sheltered bearing surface from chloride exposure. The compact pattern leaves more room for tooling than a heavy hex nut at the same nominal thread size.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Seawater exposure, access constraints, and heat-number certification
Marine valve bonnets
Inconel 625 Hex NutsMarine bonnet nuts are repeatedly removed during valve servicing and may retain seawater around their seating faces. Inconel 625 supplies localized-corrosion resistance at those interfaces. A regular hex pattern is useful on smaller or crowded bonnets where the design does not accommodate heavy hex hardware.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Chloride exposure, and heat-number certification
Flue-gas desulfurization (FGD) ducts
Inconel 625 Hex NutsAt smaller FGD cover joints, 625 hex nuts provide a compact fastening component resistant to wet chloride attack. They protect the internally threaded half of the assembly near acid-condensate leakage paths. Matching the nut to the stud avoids combining a corrosion-resistant stud with a vulnerable nut in the same exposure.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Chloride and acid exposure, and heat-number certification
Same hex nut. Different material priorities.
Inconel 625 material dataInconel 718 Hex Nuts
Around exhaust manifold branches and crowded valve bonnets, Inconel 718 hex nuts offer precipitation-hardened hot strength without the larger envelope of a heavy nut. The regular pattern preserves a path for maintenance tooling between neighbouring studs. Its specified load capacity completes the pairing with the stud.
Hastelloy C-276 Hex Nuts
Hastelloy C-276 hex nuts provide a compact corrosion-resistant component for crowded reactor, exchanger and scrubber connections. Aggressive liquid can reach both the internal threads and seating face. The regular pattern preserves tool clearance where heavy hex nuts would occupy too much space.
Monel K-500 Hex Nuts
Crowded marine bonnets leave little room between a stud, the valve neck and adjacent fittings. Monel K-500 hex nuts put age-hardened nickel-copper strength into that regular nut envelope. They suit connections whose load can be carried by the smaller pattern, leaving more radial clearance than a heavy hex nut.
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 N06625 · heat number · ordered condition
- Final-part acceptance
- Grade chemistry, supplied condition and ordered mechanical requirements.
- Dimensional record
- Thread plug gauges · Across flats · Nut height
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Matching Kit
Flange Stud Bolt Kits
Build your 625 hex nut enquiry
Questions about 625 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.