Hastelloy B-3 Socket Head Cap Screws
ISO 4762ASTM B335
Hastelloy B-3 socket head cap screws pair a nickel-molybdenum alloy with improved thermal stability relative to B-2 with compact tapped assemblies for pickling, leach, and pump hardware in hot reducing-acid service. 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
Partial thread
Use where a plain grip must span the clamped components. Match the under-head length and thread length so the screw tightens the stack before its thread runout reaches the tapped hole.
Full thread
Use for shorter component stacks and varied tapped-hole depths. The longer usable thread offers adjustment, while the screw end must clear the bottom of a blind hole.
- Drive
- Internal hex socket
- Length basis
- Under head
- Thread systems
- Metric · UNC · UNF · UNJ
- Assembly
- Tapped holes · Nuts
- Final condition
- Solution annealed
- Inspection
- Thread gauges · Head and shank dimensions
Manufacturing route
CNC machining suits samples and small lots. Cold heading or hot forging is selected for volume production according to alloy formability, head section and size.
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
Head geometry, bearing face, shank and thread fit are checked after the final machining and thermal operations.
Where B-3 fits — and what matters
Pickling tank & acid-bath hardware
Hastelloy B-3 Socket Head Cap ScrewsB-3 socket screws can secure compact covers and fixture attachments near reducing-acid baths. The recess gives access between nearby blocks or pipework, but also sees the local liquid exposure. Ferric or cupric contamination needs particular attention when assessing used pickling liquor for B-family fasteners.
Connection requirements
- Hastelloy B-3 Socket Head Cap Screws · finished condition and load requirement
- Counterbore, screw length and drive access
- Acid composition, temperature and oxidizing impurities
Acid heat exchangers & condensers
Hastelloy B-3 Socket Head Cap ScrewsB-3 socket screws secure small exchanger covers and instrument blocks exposed to strongly reducing acids. The nickel-molybdenum alloy protects the loaded screw surfaces in compatible chemistry. Axial tool access suits recessed holes between adjacent fittings, where an external hex would be difficult to engage.
Connection requirements
- Hastelloy B-3 Socket Head Cap Screws · finished condition and load requirement
- Counterbore, screw length and drive access
- Acid composition, temperature and oxidizing impurities
Chemical transfer pump casings
Hastelloy B-3 Socket Head Cap ScrewsSeal housings and compact covers on reducing-acid pumps may require socket screws close to the leakage zone. B-3 combines nickel-molybdenum corrosion resistance with axial tool access at these small joints. The form is practical where an external-hex bolt would be difficult to reach during servicing.
Connection requirements
- Hastelloy B-3 Socket Head Cap Screws · finished condition and load requirement
- Counterbore, screw length and drive access
- Acid composition, temperature and oxidizing impurities
Same socket head cap screw. Different material priorities.
Hastelloy B-3 material dataHastelloy B-2 Socket Head Cap Screws
Hastelloy B-2 socket head cap screws fit compact pump and exchanger accessories exposed to strongly reducing acids. The internal drive reaches recessed mounting holes near fittings. Chemical compatibility, particularly the absence of harmful oxidizing contamination, is the central distinction for this specialized screw.
Hastelloy C-276 Socket Head Cap Screws
Hastelloy C-276 socket head cap screws fit compact chemical-pump and delivery-system attachments with restricted wrench access. Corrosion resistance matters at the loaded screw and liquid-retaining drive recess. Axial tooling reaches recessed holes near fittings and manifold hardware.
Hastelloy C-22 Socket Head Cap Screws
Hastelloy C-22 socket head cap screws fit compact chemical-delivery and wet-process mounts exposed to mixed or oxidizing media. Axial access reaches recessed holes near congested piping. For high-purity or chamber locations, finish and cleaning requirements accompany the alloy specification.
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 gauges · Head and shank dimensions
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your B-3 socket head cap screw enquiry
Questions about B-3 socket head cap screws
What changes when the screw is stronger than the housing?
The housing thread can strip before the screw reaches its tensile capacity. The engagement depth and housing material therefore belong in the joint assessment alongside the screw’s final strength condition.