Hastelloy B-2 (UNS N10665)
The hydrochloric-acid alloy — 28 % molybdenum for all concentrations of HCl and other reducing acids — and the F468 fastener grade Ni 335.
What Hastelloy B-2 is.
Hastelloy B-2 is a nickel alloy with 26 to 30 percent molybdenum and almost no chromium. That makes it the material of choice for hydrochloric acid at all concentrations and temperatures up to boiling, and for sulfuric, phosphoric and acetic acids and hydrogen chloride gas in the absence of oxidisers. It must not be used where ferric or cupric salts, oxygen or other oxidising species are present.
ASTM B335 covers the rod. ASTM F468 and F467 list a nickel-molybdenum alloy as Ni 335, but that entry is UNS N10001, the original Hastelloy B; B-2 (N10665) is not listed in either, so B-2 fasteners are certified to B335 chemistry with the mechanical properties agreed on the order. We machine B-2 studs, bolts, nuts and components from certified B335 rod.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Nickel | Ni | balance | — |
| Molybdenum | Mo | 26.0 | 30.0 |
| Iron | Fe | — | 2.0 |
| Chromium | Cr | — | 1.0 |
| Cobalt | Co | — | 1.00 |
| Manganese | Mn | — | 1.0 |
| Carbon | C | — | 0.02 |
| Silicon | Si | — | 0.10 |
| Phosphorus | P | — | 0.04 |
| Sulfur | S | — | 0.03 |
Values per ASTM B335-03(2018) Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Mechanical properties.
| Condition and size | Tensile strength, min (ksi) | Yield strength 0.2%, min (ksi) | Elongation, min (%) |
|---|---|---|---|
| Solution annealed — 5⁄16 to 3½ in. | 110 | 51 | 40 |
Values per ASTM B335-03(2018) Table 3 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
| Nominal diameter (in.) | Hardness | Full-size tensile (ksi) | Full-size yield, min (ksi) | Machined tensile, min (ksi) | Machined yield, min (ksi) | Elongation in 4D, min (%) |
|---|---|---|---|---|---|---|
| All sizes | 20–32 HRC | 115–145 | 45 | 115 | 45 | 35 |
Values per ASTM F468-23 Table 2 (verified against the specification). F468 and F467 list Ni 335 as UNS N10001, the original Hastelloy B; N10665 (B-2) does not appear in either fastener specification, so B-2 fasteners are certified to B335 chemistry with properties agreed on the order. Confirm the edition called out on your purchase order with our estimating team. Full-size tensile range and yield; machined-specimen minimums in the last three columns.
| Nut style | Hardness, min | Proof stress, min (ksi) |
|---|---|---|
| Hex and hex flange | 20 HRC | 115 |
| Heavy hex, large hex flange and thick | 20 HRC | 124 |
Values per ASTM F467-24 Table 2 (verified against the specification). F468 and F467 list Ni 335 as UNS N10001, the original Hastelloy B; N10665 (B-2) does not appear in either fastener specification, so B-2 fasteners are certified to B335 chemistry with properties agreed on the order. Confirm the edition called out on your purchase order with our estimating team.
Specifications that apply.
How Hastelloy B-2 ships from Houston.
- Full-thread studs and stud bolts
- Hex and heavy hex bolts
- Socket head cap screws
- Hex nuts in the same alloy
- Threaded rod
- Machined components from certified bar
Hastelloy B-2 fasteners we make.
Every item is manufactured to your drawing or standard in Hastelloy B-2, imperial or metric, with an EN 10204 3.1 certificate.
What is Hastelloy B-2?
The B-family alloys are nickel-molybdenum solid solutions designed for reducing acids. Without chromium they cannot form a passive film and are attacked by any oxidising species, but in pure reducing acids, above all hydrochloric, they outlast every other engineering alloy. B-2 improved on the original alloy B by cutting carbon, silicon and iron so that welded joints stay corrosion resistant without a post-weld anneal. F468 and F467 list the older alloy B (UNS N10001) as Ni 335, at 115 to 145 ksi full-size tensile, 45 ksi yield and a 115 ksi nut proof stress; B-2 itself is not in the fastener specifications and is supplied to B335 with properties agreed on the order.
Testing, certification and marking
- Tensile and hardness tested per lot on the finished product
- Grade or alloy marking F468S on bolts and F467S on nuts and manufacturer's identification on every piece
- EN 10204 3.1 material test report with heat number and chemistry; 3.2 witness available
Hastelloy C-276 (UNS N10276)
The universal chemical-process alloy — resists oxidising and reducing acids, wet chlorine and sour gas — and the F468 fastener grade Ni 276.
ASTM B574 rodHastelloy C-22 (UNS N06022)
The higher-chromium C alloy — better than C-276 in oxidising acids, ferric and cupric chlorides and wet chlorine, with the same resistance to pitting and stress-corrosion cracking.
ASTM B446 bar · ASTM F468 / F467 fastenersInconel 625 (UNS N06625)
The corrosion all-rounder — 120 ksi in the annealed condition, resistant to seawater, sour gas, acids and oxidation to 1800 °F, and the F468 nickel fastener grade Ni 625.