Incoloy 800H Hex Nuts
ISO 4032ASTM B408
Incoloy 800H hex nuts pair a controlled-carbon, coarse-grained iron-nickel-chromium alloy with standard-height mating nuts for refinery, molten-salt, and boiler joints under sustained high-temperature load. Controlled carbon and a coarse-grained, solution-annealed structure give 800H higher creep strength than base 800 for sustained high-temperature loading.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Solution annealed
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Threads · Metric
Threads · Inch
Dimension Reference
Heat Treatment
Solution annealedThe specified solution treatment develops the controlled grain structure needed for sustained high-temperature creep duty.
What we can make in Alloy 800H
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
- 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 solution-treated condition and grain-size requirement are recorded for the ordered H or HT grade. Final dimensions are inspected after the last thermal operation.
Finished geometry
Internal thread gauging, usable engagement and bearing-face alignment are checked after final processing.
Where 800H fits — and what matters
High-temp refinery & coker flanges
Incoloy 800H Hex NutsIncoloy 800H hex nuts serve compact hot accessory-stud connections where sustained loading makes creep important. Their regular pattern leaves tool clearance around nearby cover ribs and piping. Controlled carbon and coarse grain distinguish this nut from general heat-resistant Incoloy 800; pressure-cover connections also need the corresponding finished-bolting design basis.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Sustained high-temperature duty, grade certification, and heat-number certification
Solar thermal (CSP) molten-salt piping
Incoloy 800H Hex NutsOn external support rods and compact hot-piping connections, 800H nuts can carry sustained load near molten-salt equipment without being salt-wetted parts. Their material choice addresses prolonged temperature and stress. Regular hex dimensions leave room for tooling around crowded brackets and insulation hardware.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Sustained high-temperature duty, grade certification, and heat-number certification
Boiler tube hangers & superheaters
Incoloy 800H Hex NutsIncoloy 800H nuts can adjust and retain threaded hanger connections supporting hot boiler components. Their creep-resistant material condition is useful under sustained load. A regular hex pattern fits compact support brackets, with the rod, nut and bearing plate specified as one load path.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Sustained high-temperature duty, grade certification, and heat-number certification
Same hex nut. Different material priorities.
Incoloy 800H material dataIncoloy 800 Hex Nuts
Incoloy 800 hex nuts suit compact heat-resistant cover, bracket and shield-support connections. Regular dimensions leave room around closely spaced studs, while the alloy resists oxidation. Compare 800H when sustained stress at high temperature makes creep behaviour the governing selection issue.
Nimonic 80A Hex Nuts
Nimonic 80A hex nuts fit compact hot exhaust connections and boiler support rods. Precipitation-hardened strength supports the loaded threads, while the regular pattern leaves tooling room around brackets. On threaded hangers, accessible flats also allow position adjustment during installation.
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.
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 N08810 · heat number · ordered condition
- Final-part acceptance
- UNS grade, carbon and alloy chemistry, solution-treatment record and ordered grain-size evidence.
- 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 800H hex nut enquiry
Questions about 800H 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.