Nickel Alloy Hastelloy S
UNS N06635
Hastelloy S (UNS N06635) is a solid-solution-strengthened Ni-Cr-Mo alloy from the Hastelloy corrosion-alloy family, formulated for thermal stability and fabricability rather than peak strength.
Reference datasheet — Hastelloy S is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
Hastelloy S tempers and conditions
Hastelloy S is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard stocked condition: maximum ductility and thermal stability for forming, welding and high-temperature service. | 455 | 895 | 50 | 200 HB | — |
As-welded deposit | Reference condition for all-weld-metal properties of matching Hastelloy S filler in ducting and hose end fittings; no post-weld heat treatment normally required. | 480 | 830 | 35 | 205 HB | 1.4 % IACS |
Cold drawn | Pick for close-tolerance bar, fasteners and small tube where higher yield strength and better surface are wanted over maximum ductility. | 690 | 1,000 | 30 | 25 HRC | 1.4 % IACS |
Cold worked | Use for high-temperature springs, bellows convolutions and hose braid where high strength and fatigue life are required and service temperature stays below the recrystallisation range. | 1,100 | 1,275 | 8 | 36 HRC | 1.4 % IACS |
What is Hastelloy S?
Hastelloy S (UNS N06635) is a solid-solution-strengthened Ni-Cr-Mo alloy from the Hastelloy corrosion-alloy family, formulated for thermal stability and fabricability rather than peak strength. Engineers select it for flexible, thin-gauge hot-gas hardware — sheet, strip, foil, welded tube and wire — where repeated thermal cycling and high formability (formability score 80) matter; typical properties are 455 MPa yield, 895 MPa tensile, 50 % elongation, 200 HB. Service is limited to about 1050 °C, machinability is poor (score 24), and availability is mainly restricted to thin product forms. Where higher structural strength at temperature is needed, Hastelloy X is the usual alternative. Hastelloy S has a density of 8.76 g/cm³ (0.316 lb/in³), heavier than 80% of nickel alloy grades. It melts at 1,335°C (2,435 °F). Hastelloy S has a yield strength of 455 MPa (66 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 67% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 212 GPa (30.7 Msi).
What is Hastelloy S used for?
- flexible metal hoses
- bellows and expansion joints
- aerospace ducting
Advantages
- Forms and bends easily — 80/100, better than 91% of nickel alloy grades
- Ductile — tolerates forming and impact — 50%, better than 88% of nickel alloy grades
- High service temperature — 1,050°C (1,922 °F), better than 83% of nickel alloy grades
- Readily welded — 85/100, better than 83% of nickel alloy grades
Hastelloy S properties
Typical room-temperature values for Hastelloy S-SA; bars are the position among nickel alloy grades.
Physical3
Hastelloy S has a density of 8.76 g/cm³ (0.316 lb/in³), heavier than 80% of nickel alloy grades. It melts at 1,335°C (2,435 °F).
Mechanical13
Hastelloy S has a yield strength of 455 MPa (66 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 67% of nickel alloy grades. Elongation at break is 50% and the elastic modulus is 212 GPa (30.7 Msi).
Thermal5
Hastelloy S is rated for continuous service to 1,050°C (1,922 °F). It conducts heat at 10.7 W/m·K (6.18 BTU/hr·ft·°F), worse than 68% of nickel alloy grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
Hastelloy S conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 67% of nickel alloy grades.
Sustainability4
Producing a kilogram of Hastelloy S takes about 150 MJ of energy and emits 12.5 kg of CO₂ — less than 68% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability8
Hastelloy S's machinability is poor (24/100, better than 71% of nickel alloy grades); weldability excellent (85/100); formability very good (80/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Hastelloy S is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Hastelloy S
Is Hastelloy S easy to machine?
Machine like other Hastelloy grades: rigid setup, positive-rake carbide, low speed (~15–25 m/min) with heavy feed, flood coolant, and avoid dwelling to prevent rapid work hardening.
Can Hastelloy S be welded?
Readily joined by GTAW/GMAW/resistance welding with matching S filler; keep interpass temperature low, no PWHT normally needed, and the alloy is notably resistant to strain-age cracking.
Can Hastelloy S be formed, bent or molded?
Excellent cold formability in the annealed condition (deep-drawn bellows, hose convolutions); expect high springback and forming loads, anneal at ~1065 °C between heavy operations.
Hastelloy S chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Mo | 14 – 16.5 | 15 |
| Cr | 14.5 – 17 | 15.5 |
| Fe | ≤ 3 | 1 |
| Co | ≤ 2 | |
| W | ≤ 1 | |
| Si | 0.2 – 0.75 | 0.4 |
| Mn | 0.3 – 1 | 0.5 |
| Al | ≤ 0.5 | 0.25 |
| Ti | ≤ 0.5 | |
| Larare-earth addition for oxide-scale adherence | 0.01 – 0.1 | 0.02 |
| C | ≤ 0.02 | 0.01 |
| B | ≤ 0.02 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cu | ≤ 0.35 | |
| Nibalance, nominally ~67% | balance |
What surface finishes work on Hastelloy S?
Not anodizable; use pickling/passivation, abrasive blasting or electropolish — oxide from hot forming is tenacious and needs grit blast plus acid pickle before welding.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Hastelloy S in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N06635
How much does Hastelloy S cost?
Hastelloy S is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Hastelloy S — frequently asked
What is Hastelloy S used for?
Hastelloy S is typically used for flexible metal hoses, bellows and expansion joints and aerospace ducting. In short: most formable Hastelloy sheet; strain-age crack resistant; bellows and hose grade.
What is the yield strength of Hastelloy S?
Hastelloy S has a typical yield strength of 455 MPa (66 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 67% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is Hastelloy S easy to machine?
Not especially — machinability is rated poor (24/100, better than 71% of nickel alloy grades). Machine like other Hastelloy grades: rigid setup, positive-rake carbide, low speed (~15–25 m/min) with heavy feed, flood coolant, and avoid dwelling to prevent rapid work hardening.
Can Hastelloy S be welded?
Yes — weldability is rated excellent (85/100). Readily joined by GTAW/GMAW/resistance welding with matching S filler; keep interpass temperature low, no PWHT normally needed, and the alloy is notably resistant to strain-age cracking.
What surface finishes work on Hastelloy S?
Not anodizable; use pickling/passivation, abrasive blasting or electropolish — oxide from hot forming is tenacious and needs grit blast plus acid pickle before welding.
Can Hastelloy S be formed, bent or molded?
Excellent cold formability in the annealed condition (deep-drawn bellows, hose convolutions); expect high springback and forming loads, anneal at ~1065 °C between heavy operations.
What is the maximum service temperature of Hastelloy S?
Hastelloy S is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Hastelloy S-SA and Hastelloy S-CW?
SA is the default condition — standard stocked condition: maximum ductility and thermal stability for forming, welding and high-temperature service. CW: use for high-temperature springs, bellows convolutions and hose braid where high strength and fatigue life are required and service temperature stays below the recrystallisation range. Yield strength is 455 MPa in SA versus 1,100 MPa in CW.
How much does Hastelloy S cost?
Hastelloy S is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- HASTELLOY S alloy product brochure (UNS N06635) — Haynes International (2020)
- ASTM B435 / B572 / B619 — Ni-Cr-Mo alloy sheet, rod and welded pipe (N06635 covered chemistry) — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys — ASM International (2000)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.