HASTELLOY B2 FASTENERS | ULTIMATE GUIDE & MANUFACTURER

Ananka Fasteners is a premier manufacturer and supplier of high-quality Hastelloy B2 Fasteners (UNS N10665 / W.Nr. 2.4617). Engineered as a premier solid solution strengthened, nickel-molybdenum alloy, B2 offers unmatched resistance to highly reducing environments—most notably boiling hydrochloric and sulfuric acids—making it the ultimate fastening solution where standard stainless steels and chromium-rich alloys fail.

As a master manufacturer, we produce a comprehensive range of Alloy B2 fasteners spanning from standard M3 hardware to massive M100 structural ties.

Explore our dedicated standard pages for specific fastener categories to view detailed dimensions, availability, and specific technical data:

• Hastelloy B2 Bolts: Comprehensive range of heavy hex, socket cap, and anchor configurations.
• Hastelloy B2 Nuts: View our dedicated page for standard hex, heavy hex, and precision-machined nuts.
• Hastelloy B2 Studs: Fully threaded and double-ended studs for highly reducing high-pressure joints.
• Hastelloy B2 Washers: High-performance plain, lock, and spring washers for secure fastening in corrosive environments.

■ Hastelloy B2 Material Specifications

Material Equivalent Grades	UNS N10665 | W.Nr. 2.4617 | Alloy B2 | NiMo28 | AFNOR NU-30M
Standard Specifications	ASTM F468 / ASME SF468 (Nonferrous Bolts & Studs) ASTM B335 / ASME SB335 (Rod & Bar Stock)
Size Range	Metric: M3 to M100 (M56 commonly stocked) | Imperial: 3/16" to 4"
Thread Types	UNC, UNF, Metric Coarse, Metric Fine, BSW, BSF
Dimensional Standards	DIN (931/933/912/934/976), ISO, ASME

■ Chemical Composition of Alloy B2

Ni (Nickel)	Mo (Molybdenum)	Fe (Iron)	Cr (Chromium)	Co (Cobalt)	Mn (Manganese)	Si (Silicon)	C (Carbon)
69.0% Bal	26.0 - 30.0%	2.00% Max	1.00% Max	1.00% Max	1.00% Max	0.10% Max	0.02% Max

■ Mechanical & Physical Properties

Tensile Strength (Min)	Yield Strength 0.2% Offset (Min)	Elongation (%)	Density	Melting Range
760 MPa (110 ksi)	350 MPa (51 ksi)	40% Min	9.22 g/cm³	1300 - 1380°C

■ Installation Tribology & Corrosion Profile

Installation: Nickel-molybdenum superalloys exhibit a high propensity to gall (cold weld) during installation. The application of engineered, nickel-compatible anti-seize lubricants is strictly mandatory during joint assembly to ensure accurate torque-to-tension conversion.

Corrosion Vulnerability Warning: Because Alloy B2 intentionally restricts Chromium (1.00% Max) to maximize performance in reducing acids, it cannot form a robust passive oxide layer. Hastelloy B2 fasteners should never be used in oxidizing environments or in the presence of oxidizing salts (such as ferric or cupric chloride), as they will suffer premature failure.

■ Key Characteristics & Industrial Applications

Hastelloy B2 is completely unmatched in its resistance to pure hydrochloric acid at all concentrations and temperatures, making it a critical asset in specific harsh environments.

• Chemical Processing: Exclusive reliance for reactors, heat exchangers, and distillation columns handling pure hydrochloric, sulfuric, and phosphoric acids.
• Pharmaceutical Production: Securing pharmaceutical reactors and complex piping systems synthesizing APIs using harsh reducing chemicals, ensuring zero metallic contamination.
• Vacuum Furnaces & Mechanical Components: High-temperature vacuum or inert gas environments where oxidation is not a threat, but high structural strength is required up to 815°C (1500°F).
Strategic Material Specification: While C276 and C22 are favored for mixed or oxidizing acids, Hastelloy B2 stands alone as the ultimate fastener material for severely reducing environments. Specifying Hastelloy B2 fasteners in pure reducing chemical operations guarantees structural survival, prevents catastrophic leaks, and permanently resolves corrosion-based failure mechanisms.