Tungsten Alloy 97W-2.1Ni-0.9Fe-SR (Stress relieved)
Heat-treated state
ASTM B777 Class 4
Used for thin or close-tolerance machined parts where distortion after finish machining must be minimised.
Values for the SR condition
Other 97W-2.1Ni-0.9Fe tempers and conditions
97W-2.1Ni-0.9Fe is listed in 3 conditions; see the grade overview at 97W-2.1Ni-0.9Fe.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Used for thin or close-tolerance machined parts where distortion after finish machining must be minimised. | 580 | 690 | 5 | 29 HRC | 15 % IACS |
Sintered + vacuum heat treated and quenched | Choose when maximum elongation and impact toughness are needed (kinetic-energy penetrators, dynamically loaded rotors); the anneal removes hydrogen and dissolves brittle intermetallics. | 610 | 730 | 7 | 28 HRC | 15 % IACS |
Swaged / cold worked (≈10–20 % reduction) and aged | Specify for the highest strength and hardness in rod form (penetrator cores, high-load pins); ductility and toughness drop sharply and only simple round sections are available. | 900 | 1,000 | 2 | 38 HRC | 14 % IACS |
What is 97W-2.1Ni-0.9Fe-SR?
97W-2.1Ni-0.9Fe-SR is 97W-2.1Ni-0.9Fe heat treated to SR — used for thin or close-tolerance machined parts where distortion after finish machining must be minimised. 97W-2.1Ni-0.9Fe-SR has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 83% of tungsten alloy grades. Elongation at break is 5% and the elastic modulus is 390 GPa (56.6 Msi). 97W-2.1Ni-0.9Fe-SR has a density of 18.5 g/cm³ (0.668 lb/in³), lighter than 62% of tungsten alloy grades. It melts at 1,455°C (2,651 °F).
Advantages
- Easy to machine — 42/100, better than 105% of tungsten alloy grades
- Tough — resists crack growth — 45 MPa·√m (41 ksi·√in), better than 95% of tungsten alloy grades
- Ductile — tolerates forming and impact — 5%, better than 85% of tungsten alloy grades
Limitations
- Needs corrosion protection — 45/100, worse than 86% of tungsten alloy grades
- Low strength — 580 MPa (84.1 ksi), worse than 83% of tungsten alloy grades
97W-2.1Ni-0.9Fe-SR properties
Typical room-temperature values for 97W-2.1Ni-0.9Fe-SR; 22 are specific to this condition. Other listed values are 97W-2.1Ni-0.9Fe reference data and may not represent this condition. Bars are the position among tungsten alloy grades.
Physical3
97W-2.1Ni-0.9Fe-SR has a density of 18.5 g/cm³ (0.668 lb/in³), lighter than 62% of tungsten alloy grades. It melts at 1,455°C (2,651 °F).
Mechanical16
97W-2.1Ni-0.9Fe-SR has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 83% of tungsten alloy grades. Elongation at break is 5% and the elastic modulus is 390 GPa (56.6 Msi).
Thermal5
97W-2.1Ni-0.9Fe-SR is rated for continuous service to 500°C (932 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), worse than 62% of tungsten alloy grades. Thermal expansion is 4.3 µm/m·K (2.39 µin/in·°F).
Electrical3
97W-2.1Ni-0.9Fe-SR conducts electricity at 15 % IACS, worse than 69% of tungsten alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 86% of tungsten alloy grades.
Sustainability4
Producing a kilogram of 97W-2.1Ni-0.9Fe-SR takes about 380 MJ of energy and emits 26 kg of CO₂ — less than 62% of tungsten alloy grades. Typical recycled content is 25%.
Manufacturability8
97W-2.1Ni-0.9Fe-SR's machinability is fair (42/100, better than 105% of tungsten alloy grades); weldability poor (15/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 97W-2.1Ni-0.9Fe-SR
Is 97W-2.1Ni-0.9Fe easy to machine?
Machinable with sharp carbide or CBN tooling at low speed, high feed and rigid setups — treat like a hard cast iron; grinding and EDM are common for finishing, and dust must be collected (Ni/Co-free but respirable).
Can 97W-2.1Ni-0.9Fe be welded?
Effectively unweldable by fusion (binder segregation and cracking); join by silver/copper brazing, shrink fit, threading or adhesive, with EB/laser welding only for qualified special cases.
Can 97W-2.1Ni-0.9Fe be formed, bent or molded?
Net-shape by press-and-liquid-phase-sinter at 1450–1500 °C with ~18–20 % linear shrinkage; at 97 % W only limited rotary swaging of round bar is feasible, no sheet forming.
What surface finishes work on 97W-2.1Ni-0.9Fe?
No anodizing; parts are supplied ground, oiled, electroless-nickel or chrome plated, or epoxy-painted for humid and salt-spray environments.
97W-2.1Ni-0.9Fe 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 |
|---|---|---|
| WASTM B777 Class 4 requires 97 % W nominal; density class controls acceptance | 96.5 – 97.5 | 97 |
| Nibinder phase, Ni:Fe ≈ 7:3 | 1.8 – 2.4 | 2.1 |
| Cimpurity — carbon forms brittle carbides | ≤ 0.02 | 0.01 |
| Oimpurity | ≤ 0.02 | 0.01 |
| Febalance of Ni+Fe binder | ≥ 0.7 (balance) | — |
97W-2.1Ni-0.9Fe-SR — frequently asked
What is 97W-2.1Ni-0.9Fe-SR used for?
97W-2.1Ni-0.9Fe-SR is typically used for kinetic energy penetrators, aerospace balance weights, gyroscope rotors and radiation shielding. In short: near-maximum density, 18.5 g/cm³; highest-tungsten heavy alloy; low ductility, not weldable.
What is the yield strength of 97W-2.1Ni-0.9Fe-SR?
97W-2.1Ni-0.9Fe-SR has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 690 MPa (100 ksi) — weaker than 83% of tungsten alloy grades. Strength varies by condition: see the 3 listed tempers.
Is 97W-2.1Ni-0.9Fe-SR easy to machine?
Not especially — machinability is rated fair (42/100, better than 105% of tungsten alloy grades). Machinable with sharp carbide or CBN tooling at low speed, high feed and rigid setups — treat like a hard cast iron; grinding and EDM are common for finishing, and dust must be collected (Ni/Co-free but respirable).
Can 97W-2.1Ni-0.9Fe-SR be welded?
Not readily — weldability is rated poor (15/100). Effectively unweldable by fusion (binder segregation and cracking); join by silver/copper brazing, shrink fit, threading or adhesive, with EB/laser welding only for qualified special cases.
What surface finishes work on 97W-2.1Ni-0.9Fe-SR?
No anodizing; parts are supplied ground, oiled, electroless-nickel or chrome plated, or epoxy-painted for humid and salt-spray environments.
Can 97W-2.1Ni-0.9Fe-SR be formed, bent or molded?
Net-shape by press-and-liquid-phase-sinter at 1450–1500 °C with ~18–20 % linear shrinkage; at 97 % W only limited rotary swaging of round bar is feasible, no sheet forming.
What is the maximum service temperature of 97W-2.1Ni-0.9Fe-SR?
97W-2.1Ni-0.9Fe-SR is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM B777 – Standard Specification for Tungsten Base, High-Density Metal — ASTM International (2022)
- ASM Handbook Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Tungsten Heavy Alloys) — ASM International (1990)
- Tungsten heavy alloy (W-Ni-Fe) grade datasheets — Plansee / Wolfmet / Mi-Tech Metals (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.