Monel K-500 Hex Nuts
ISO 4032ASTM B865
Monel K-500 hex nuts pair an age-hardened nickel-copper alloy with a standard-height mating nut for marine bolt and stud systems. Paired with matching K-500 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 / age hardened
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 age hardenedAnnealing provides a workable starting condition, while controlled aging develops the higher strength specified for age-hardened K-500.
What we can make in Monel K-500
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 · age hardened
- 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 K-500 fits — and what matters
Seawater pumps
Monel K-500 Hex NutsRegular hex K-500 nuts fit pump brackets and cover connections where a heavy hex pattern would crowd adjacent ribs or fittings. The age-hardened alloy provides a stronger nickel-copper nut option for marine exposure. Its smaller footprint makes the bearing surface beneath the nut an important assembly detail.
Connection requirements
- Mating bolt diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Seawater exposure, age-hardened condition, and heat-number certification
Marine valve bonnets
Monel K-500 Hex NutsValve bonnet studs sometimes sit close to the neck or actuator support. A regular hex nut gives more tool clearance than a heavy pattern, while K-500 keeps the material choice consistent with high-strength nickel-copper bolting. The nut's specified proof load establishes whether that compact pattern suits the stud load.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Chloride exposure, age-hardened condition, and heat-number certification
Plate & shell heat-exchanger covers
Monel K-500 Hex NutsOn a seawater heat-exchanger cover with closely spaced studs, regular K-500 nuts offer an aged nickel-copper component without a heavy hex nut's footprint. They suit a design that needs the specified nut strength while leaving enough tool clearance for repeated cover removal.
Connection requirements
- Mating bolt diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Chloride exposure, age-hardened condition, and heat-number certification
Same hex nut. Different material priorities.
Monel K-500 material dataInconel 625 Hex Nuts
Inconel 625 hex nuts suit compact offshore, marine-bonnet and FGD connections exposed to wet chlorides. The alloy resists localized corrosion at internal threads and sheltered seating faces. A regular pattern leaves more tooling clearance than a heavy nut on the same nominal thread.
Inconel 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.
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 N05500 · 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
Matching Kit
Flange Stud Bolt Kits
Build your K-500 hex nut enquiry
Questions about K-500 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.