ASTM B366 C-4 · NiMo16Cr16Ti No W — Better Thermal Stability

2.4610 (Hastelloy C-4) Pipe Fittings

ASTM B366 buttweld pipe fittings in 2.4610 — Hastelloy C-4 (NiMo16Cr16Ti, N06455). A Ni-Cr-Mo alloy without tungsten. The absence of W makes C-4 more thermally stable than C-276 in the 650–1040°C range — less prone to grain boundary precipitation. This thermal stability is the key selection criterion. Corrosion performance similar to C-276 in reducing environments; matched by Ti addition for stabilisation.

PRE (approx.)

~62

Key Difference

No W — thermal stability

ASTM UNS

N06455

Hastelloy C Family Selection

Grade	W.Nr.	Cr %	Mo %	W	Key Advantage
C-276	2.4819	15–17%	15–17%	3–4.5%	Best all-round; reducing acids, highest PRE
C-4 (this grade)	2.4610	14–18%	14–17%	None	Superior thermal stability — no W precipitation
C-22	2.4602	20–22.5%	12.5–14.5%	2.5–3.5%	High Cr for oxidising + reducing media

When to Choose C-4 over C-276

Specify C-4 (2.4610) when the component will be exposed to sustained temperatures in the 650–1040°C range in service or during fabrication (stress relief, PWHT, or process excursions). The W in C-276 promotes μ-phase and P-phase precipitation at these temperatures, reducing corrosion resistance. C-4 with Ti stabilisation avoids this. For purely ambient-temperature service with no thermal excursion risk, C-276 provides equivalent or slightly higher corrosion resistance and is typically the first-choice grade.

Cross-References

W.Nr.	2.4610
EN Name	NiMo16Cr16Ti
ASTM UNS	N06455
Trade Name	Hastelloy C-4

Welding

Filler: ERNiCrMo-7 (C-4 matching). No PWHT. Excellent thermal stability post-weld — a primary advantage over C-276.

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Testing & Inspection

✓ Chemical analysis against the ordered material standard / ASTM B366
✓ Tensile test, with impact test where the standard or your order requires it
✓ PMI confirming Ni, Cr and Mo content
✓ PMI (positive material identification) on every order
✓ Visual and dimensional inspection to ASME B16.9
✓ NDT (UT, RT, MT or PT) when your order or code calls for it
✓ EN 10204 3.1 certificate as standard; 3.2 with TÜV, Lloyd's Register, Bureau Veritas, DNV or your own inspector

Size Range

DN15–DN600 and larger. Outside diameters follow the EN 10220 / EN ISO 1127 pipe series; wall thickness is matched to your connecting pipe.

Size	OD (mm)
DN 15	21.3
DN 20	26.9
DN 25	33.7
DN 32	42.4
DN 40	48.3
DN 50	60.3
DN 65	76.1
DN 80	88.9
DN 100	114.3
DN 125	139.7
DN 150	168.3
DN 200	219.1
DN 250	273.0
DN 300	323.9
DN 350	355.6
DN 400	406.4
DN 450	457.0
DN 500	508.0
DN 600	610.0

Export Documents & Packing

✓ Commercial invoice, packing list and certificate of origin
✓ EN 10204 certificates with heat-number traceability
✓ PED 2014/68/EU and AD 2000-Merkblatt W0 documentation for European projects
✓ Seaworthy wooden cases or pallets, bevel ends protected, marked to your instructions
✓ FOB, CFR or CIF delivery terms

Request a Hastelloy C-4 (2.4610) Quote

Frequently Asked Questions: Hastelloy C-4 (2.4610) Fittings

What is the difference between Hastelloy C-4 and C-276?

C-4 contains no tungsten, which makes it more thermally stable in the 650–1040°C range and less prone to grain-boundary precipitation.

What is the designation of Hastelloy C-4?

EN 2.4610, NiMo16Cr16Ti, UNS N06455.

Which certificates come with C-4 fittings?

EN 10204 3.1 as standard, or 3.2 with third-party inspection.