Hastelloy B-3 Stud Bolts
ASME B18.31.2ASTM B335
Hastelloy B-3 stud bolts pair a nickel-molybdenum alloy with improved thermal stability relative to B-2 with double-ended closure for autoclave, reactor, and exchanger joints under hot reducing-acid duty. Compared with B-2, B-3 forms embrittling phases more slowly during intermediate-temperature exposure, giving more processing flexibility while retaining resistance to reducing acids.
- 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-3
Fully threaded
Two nuts clamp the flange or cover; usable thread length spans the assembled grip.
Double-end
A plain centre spans the grip, with a threaded portion at each end for the nuts.
Tap-end
One end engages a tapped casing; the exposed end accepts the cover nut.
- Threads
- Metric · UNC · UNF · 8UN · UNJ
- Forms
- Continuous thread · Double-end · Tap-end
- Final condition
- Solution annealed
- Inspection
- Thread size and fit; overall and effective thread length; end geometry; lot identification.
Manufacturing route
CNC machining suits samples and special end forms. Repeat lots use cut-to-length stock with rolling or cutting selected for the ordered thread and material condition.
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
End lengths, runout and effective thread engagement are checked separately from overall length; tap ends are gauged to their own fit requirement.
Where B-3 fits — and what matters
Reactor vessel & manway flanges
Hastelloy B-3 Stud BoltsB-3 studs suit reactor manways in compatible reducing-acid service. Their corrosion resistance is useful at the threads and shank near the gasket edge. With a tapped-stud flange, the fasteners can remain installed while crews remove the nuts and cover for internal inspection.
Connection requirements
- Hastelloy B-3 Stud Bolts · finished condition and load requirement
- Stud length, nut pattern and thread engagement
- Acid composition, temperature and oxidizing impurities
Acid heat exchangers & condensers
Hastelloy B-3 Stud BoltsOn reducing-acid exchanger channel covers, B-3 studs combine an accessible nut-and-cover arrangement with nickel-molybdenum corrosion resistance. Acid reaching the gasket-edge fasteners is the relevant exposure. Studs can stay in place during repeated cover removal, reducing disturbance of the flange's tapped mounting holes where those are used.
Connection requirements
- Hastelloy B-3 Stud Bolts · finished condition and load requirement
- Stud length, nut pattern and thread engagement
- Acid composition, temperature and oxidizing impurities
Chemical transfer pump casings
Hastelloy B-3 Stud BoltsB-3 studs can secure chemical-pump casing covers in compatible reducing-acid circuits. They guide the cover into place and accept nuts on the accessible face. The alloy choice protects the fastening surfaces reached by process leakage; the pump's actual acid composition, including contaminants, determines compatibility.
Connection requirements
- Hastelloy B-3 Stud Bolts · finished condition and load requirement
- Stud length, nut pattern and thread engagement
- Acid composition, temperature and oxidizing impurities
Same stud. Different material priorities.
Hastelloy B-3 material dataHastelloy B-2 Stud Bolts
Hastelloy B-2 studs suit repeatedly opened covers and flanges in strongly reducing acid circuits. Removable nuts provide access while body-mounted studs remain installed. Corrosion resistance depends on compatible chemistry, with oxidizing metal ions in used baths a key reason to reconsider B-2.
Hastelloy C-276 Stud Bolts
Hastelloy C-276 studs suit repeatedly opened reactor, scrubber and acid-exchanger covers exposed to corrosive deposits or process leakage. The alloy protects the loaded stud surfaces in compatible mixed chemical media. Removable nuts provide access while body-mounted studs can remain installed.
Hastelloy C-22 Stud Bolts
Hastelloy C-22 studs suit serviceable pump and reactor covers where process mixtures or cleaning cycles change the chemical exposure. Broad corrosion resistance protects exposed threads and shanks. Fixed studs also assist cover positioning before accessible nuts are tightened.
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 N10675 · heat number · ordered condition
- Final-part acceptance
- Grade chemistry, supplied condition and ordered mechanical requirements.
- Dimensional record
- Thread size and fit; overall and effective thread length; end geometry; lot identification.
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Matching Kit
Flange Stud Bolt Kits
Build your B-3 stud enquiry
Questions about B-3 stud bolts & threaded rods
Does changing the stud alloy also change the nut selection?
The nut needs compatible internal threads, sufficient engaged height and a specified material condition. Select lubricant or surface treatment with the stud–nut pair, because assembly friction affects the preload obtained from tightening.