Tungsten Alloy Pure W Stress Relieved
Heat-treated state
also CP Tungsten
Use when machining/EDM distortion or residual-stress cracking must be avoided while keeping most of the wrought strength and fine grain.
Values for the Stress Relieved condition
Other Pure W tempers and conditions
Pure W is listed in 7 conditions; see the grade overview at Pure W.
- Sintered
- As Printed
- HIP
- Recrystallized
- Stress Relieved
- Forged
- As Rolled
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
pressed and vacuum/hydrogen sintered, ~95–98 % of theoretical density | Cheapest near-net P/M form for shielding blocks, crucibles and simple electrodes where residual porosity and low strength are acceptable. | 300 | 350 | 0.5 | 29 HRC | 26 % IACS |
laser powder-bed fusion (LPBF/SLM) or EBM pure W, as-built | For complex collimators, heat sinks and plasma-facing geometries impossible to machine; expect 96–99 % density, solidification microcracking, anisotropy and near-zero ductility — HIP or stress relief is normally added. | 320 | 350 | 0.3 | 39 HRC | 120 W/m·K |
Hot isostatic pressed | Pick for large, complex or additively made W parts needing pore-free, leak-tight, isotropic material without a wrought texture. | 380 | 480 | 1 | 33 HRC | 168 W/m·K |
heated above ~1400 °C, equiaxed grains | The state reached after high-temperature service or welding: softest and most brittle at room temperature, chosen only for parts that operate hot and dimensionally stable. | 400 | 550 | 1.5 | 33 HRC | 172 W/m·K |
Stress RelievedThis page wrought W annealed below recrystallization (~900–1200 °C) | Use when machining/EDM distortion or residual-stress cracking must be avoided while keeping most of the wrought strength and fine grain. | 550 | 700 | 5 | 35 HRC | 31 % IACS |
Pressed, sintered and hot-forged/upset bar, disc or block | Choose for thick bar, discs and crucible/electrode blanks where full density and more isotropic properties matter more than peak sheet strength. | 620 | 750 | 3 | 37 HRC | 165 W/m·K |
As RolledDefault pressed, sintered and warm/hot rolled sheet, plate or foil | Default stocked wrought condition for plate, sheet and foil: highest strength and hardness, fibrous texture, minimum room-temperature ductility still usable for flat parts and shielding. | 700 | 800 | 3 | 38 HRC | 165 W/m·K |
What is Pure W Stress Relieved?
Pure W Stress Relieved is Pure W heat treated to Stress Relieved — use when machining/EDM distortion or residual-stress cracking must be avoided while keeping most of the wrought strength and fine grain. Pure W Stress Relieved has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 5% and the elastic modulus is 400 GPa (58 Msi). Pure W Stress Relieved has a density of 19.25 g/cm³ (0.695 lb/in³), heavier than 76% of tungsten alloy grades. It melts at 3,422°C (6,192 °F). As Rolled is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 5%, better than 85% of tungsten alloy grades
Limitations
- Low strength — 550 MPa (79.8 ksi), worse than 89% of tungsten alloy grades
Pure W Stress Relieved properties
Typical room-temperature values for Pure W Stress Relieved; 22 are specific to this condition. Other listed values are Pure W reference data and may not represent this condition. Bars are the position among tungsten alloy grades.
Physical3
Pure W Stress Relieved has a density of 19.25 g/cm³ (0.695 lb/in³), heavier than 76% of tungsten alloy grades. It melts at 3,422°C (6,192 °F).
Mechanical16
Pure W Stress Relieved has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 5% and the elastic modulus is 400 GPa (58 Msi).
Thermal6
Pure W Stress Relieved is rated for continuous service to 500°C (932 °F). It conducts heat at 168 W/m·K (97.1 BTU/hr·ft·°F), better than 76% of tungsten alloy grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).
Electrical3
Pure W Stress Relieved conducts electricity at 31 % IACS, better than 83% of tungsten alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), better than 50% of tungsten alloy grades.
Sustainability3
Producing a kilogram of Pure W Stress Relieved takes about 400 MJ of energy and emits 27 kg of CO₂ — more than 74% of tungsten alloy grades. Typical recycled content is 30%.
Manufacturability8
Pure W Stress Relieved's machinability is not recommended (10/100, better than 52% of tungsten alloy grades); weldability not recommended (12/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Pure W Stress Relieved
Is Pure W easy to machine?
Treat as a brittle hard metal: grinding, EDM/wire-EDM and laser cutting are preferred; if turning/milling, use rigid setups, negative-rake carbide or CBN, low speed, heavy flood coolant and preheat 200–400 °C to avoid chipping.
Can Pure W be welded?
Essentially unweldable by arc processes — electron-beam or laser welding in high vacuum with preheat is possible but the weld recrystallizes and becomes brittle; joining is normally by brazing (Ni-, Cu-, Ag-Cu-Ti fillers) or mechanical/diffusion bonding.
Can Pure W be formed, bent or molded?
No practical cold forming; roll, swage, forge or bend hot (typically 1000–1500 °C, above the DBTT) with intermediate stress-relief anneals; complex shapes come from powder pressing, CIP+sinter+HIP or LPBF.
What surface finishes work on Pure W?
Not anodizable; grind and lap to a fine finish, then electropolish or acid-clean; for oxidation service above 500 °C apply Si/aluminide, CVD/PVD or Ni/Cr diffusion coatings, and use Ni or Au plating for solderability.
Pure W 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 | ≤ 0.01 | 0 |
| Fe | ≤ 0.01 | 0 |
| Ni | ≤ 0.01 | 0 |
| C | ≤ 0 | 0 |
| Ohigher in as-sintered and printed material | ≤ 0.01 | 0 |
| Si | ≤ 0 | 0 |
| Al | ≤ 0 | 0 |
| Ca | ≤ 0 | 0 |
| Cr | ≤ 0 | 0 |
| Cu | ≤ 0 | 0 |
| Mg | ≤ 0 | 0 |
| Kdoped (AKS) wire grades intentionally higher | ≤ 0 | 5×10⁻⁴ |
| WPurity on a metallic basis, ASTM B760/GB/T 3875 class | ≥ 99.95 (balance) |
Pure W Stress Relieved — frequently asked
What is Pure W Stress Relieved used for?
Pure W Stress Relieved is typically used for X-ray tube anodes, radiation shielding blocks and collimators, GTAW welding electrodes, furnace hot-zone elements and shields, ion- and plasma-facing components and EDM electrodes. In short: high-density tungsten rod.
What is the yield strength of Pure W Stress Relieved?
Pure W Stress Relieved has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Strength varies by condition: see the 7 listed tempers.
Is Pure W Stress Relieved easy to machine?
Not especially — machinability is rated not recommended (10/100, better than 52% of tungsten alloy grades). Treat as a brittle hard metal: grinding, EDM/wire-EDM and laser cutting are preferred; if turning/milling, use rigid setups, negative-rake carbide or CBN, low speed, heavy flood coolant and preheat 200–400 °C to avoid chipping.
Can Pure W Stress Relieved be welded?
Not readily — weldability is rated not recommended (12/100). Essentially unweldable by arc processes — electron-beam or laser welding in high vacuum with preheat is possible but the weld recrystallizes and becomes brittle; joining is normally by brazing (Ni-, Cu-, Ag-Cu-Ti fillers) or mechanical/diffusion bonding.
What surface finishes work on Pure W Stress Relieved?
Not anodizable; grind and lap to a fine finish, then electropolish or acid-clean; for oxidation service above 500 °C apply Si/aluminide, CVD/PVD or Ni/Cr diffusion coatings, and use Ni or Au plating for solderability.
Can Pure W Stress Relieved be formed, bent or molded?
No practical cold forming; roll, swage, forge or bend hot (typically 1000–1500 °C, above the DBTT) with intermediate stress-relief anneals; complex shapes come from powder pressing, CIP+sinter+HIP or LPBF.
What is the maximum service temperature of Pure W Stress Relieved?
Pure W Stress Relieved 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.
What is the difference between Pure W As Rolled and Pure W-HIP?
As Rolled is the default condition — default stocked wrought condition for plate, sheet and foil: highest strength and hardness, fibrous texture, minimum room-temperature ductility still usable for flat parts and shielding. HIP: pick for large, complex or additively made W parts needing pore-free, leak-tight, isotropic material without a wrought texture. Yield strength is 700 MPa in As Rolled versus 380 MPa in HIP.
Sources
- ASTM B760 – Tungsten Plate, Sheet and Foil — ASTM (2022)
- ASTM B777 / ASTM B459 tungsten product specifications — ASTM (2020)
- GB/T 3875 / GB/T 4181 — SAC (2017)
- ASM Handbook Vol.2 — Properties of Refractory Metals — ASM International (1990)
- Tungsten material properties (sintered, rolled, forged, wire) — Plansee SE (2023)
- Pure tungsten product data — Midwest Tungsten Service (2023)
- CRC Handbook of Chemistry and Physics — physical constants of W — CRC Press (2020)
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.