Hastelloy B-2 Heavy Hex Nuts
ASME B18.2.2
Hastelloy B-2 heavy hex nuts pair a nickel-molybdenum alloy with a larger bearing face for reactor and pump joints in reducing-acid service, where nut-face load distribution matters as much as thread strength. 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
- 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 Heavy Hex NutsB-2 heavy hex nuts protect the internally threaded side of reducing-acid reactor flange assemblies. The large bearing footprint suits substantial manway studs, while the nickel-molybdenum alloy resists compatible acid exposure beneath the nut. Matching the nut's proof load and material condition to the stud completes this assembly choice.
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 Heavy Hex NutsAt acid-pump covers, the nut seating face and internal threads can hold process liquid after a leak. B-2 heavy hex nuts are useful for compatible reducing-acid duty at those surfaces. Their substantial flats suit maintenance tooling where the casing provides enough clearance for a heavy pattern.
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
Pickling tank & acid-bath hardware
Hastelloy B-2 Heavy Hex NutsHeavy hex B-2 nuts are candidates for substantial pickling-equipment cover studs in a compatible reducing-acid circuit. The bath composition, including oxidizing contamination, determines suitability at the seat and threads where liquid remains. The cover spotface must accommodate the required bearing pattern and nut load.
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 heavy hex nut. Different material priorities.
Hastelloy B-2 material dataHastelloy B-3 Heavy Hex Nuts
Hastelloy B-3 heavy hex nuts suit robust reducing-acid stud assemblies where liquid can remain beneath the bearing face. Broad seating contact supports substantial cover spotfaces. B-3 offers improved thermal stability over B-2, while compatibility still depends on the absence of harmful oxidizing contamination.
Hastelloy C-276 Heavy Hex Nuts
Hastelloy C-276 heavy hex nuts carry stud loads at corrosive reactor and exchanger covers. Their broad seating faces suit substantial spotfaces, and the alloy resists attack inside the loaded threads and beneath the nut. The heavy pattern is useful where maintenance tooling has adequate clearance.
Hastelloy C-22 Heavy Hex Nuts
Hastelloy C-22 heavy hex nuts suit substantial cover studs exposed to oxidizing or mixed chemical media. Corrosion resistance matters inside the threads and beneath the bearing face, where liquid can persist. The heavy pattern provides broad seating contact and robust maintenance-tool engagement.
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
Build your B-2 heavy 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.