Hastelloy B-2 Hex Nuts
ISO 4032
Hastelloy B-2 hex nuts pair a nickel-molybdenum alloy with standard-height mating nuts for reactor, exchanger, and pump joints in reducing-acid service. The alloy resists reducing-acid attack at nut faces and threads.
- 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 annealedSolution annealing dissolves detrimental precipitates, followed by rapid cooling to preserve corrosion resistance.
What we can make in Hastelloy B-2
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 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 B-2 fits — and what matters
Reactor vessel & manway flanges
Hastelloy B-2 Hex NutsRegular hex B-2 nuts fit reactor accessory studs and smaller covers in compatible reducing-acid service. The alloy protects the internal threads and seating face where acid can remain after a leak. Their compact pattern is useful around closely spaced hardware that cannot accommodate a heavy hex nut.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Reducing-acid chemistry, oxidising-contaminant exclusion, and heat-number certification
Acid heat exchangers & condensers
Hastelloy B-2 Hex NutsB-2 nuts can accompany exchanger cover studs exposed to compatible reducing-acid leakage. The regular pattern leaves tool space between closely spaced fasteners. Specify both threaded components for that exposure and the required cover load.
Connection requirements
- Mating stud diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Reducing-acid chemistry, oxidising-contaminant exclusion, and heat-number certification
Chemical transfer pump casings
Hastelloy B-2 Hex NutsSmall acid-pump cover and mounting connections can use regular hex B-2 nuts where the process is compatible with this nickel-molybdenum alloy. The smaller nut envelope helps around casing ribs and pipe fittings. Chemical resistance at the threads is the main reason to select B-2 here.
Connection requirements
- Mating bolt diameter, thread form, and thread class
- Nut height, width across flats, and bearing-face condition required
- Reducing-acid chemistry, oxidising-contaminant exclusion, and heat-number certification
Same hex nut. Different material priorities.
Hastelloy B-2 material dataHastelloy B-3 Hex Nuts
Hastelloy B-3 hex nuts suit compact cover and auxiliary connections exposed to strongly reducing acids. Their regular pattern preserves tooling space around close studs. The alloy offers improved thermal stability over B-2, with oxidizing impurities and cleaning chemistry remaining essential selection details.
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.
Hastelloy C-22 Hex Nuts
Hastelloy C-22 hex nuts secure compact reactor, exchanger and abatement connections exposed to mixed chemical condensate. The alloy resists attack on the loaded threads and sheltered bearing face. Regular dimensions preserve tooling clearance around closely spaced cover studs and ductwork.
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 N10665 · 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 B-2 hex nut enquiry
Questions about B-2 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.