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Tungsten Alloy EWP (WP)-RX (Recrystallised)

Heat-treated state

AISI/SAE AWS A5.12 EWP · GB GB/T 4189 WP · ISO 6848 WP

Condition of the electrode zone heated above ~1300–1500 °C in service or by anneal: coarse equiaxed grains, much lower strength and near-zero room-temperature ductility (tip splitting).

High cost $$$$

Values for the RX condition

Other EWP (WP) tempers and conditions

EWP (WP) is listed in 3 conditions; see the grade overview at EWP (WP).

Compare all 3 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
RXThis page
Recrystallised
Condition of the electrode zone heated above ~1300–1500 °C in service or by anneal: coarse equiaxed grains, much lower strength and near-zero room-temperature ductility (tip splitting).4205000.535 HRC32 % IACS
As-swaged black (unground) rod
Cheapest form, oxide/lubricant film left on the surface; used for heavy AC work or where the electrode is dressed before use.7201,050245 HRC30 % IACS
GFDefault
Ground (polished) finish rod, as-swaged/drawn condition
Standard stocked condition: centreless-ground bright surface for best current transfer and clean arc starts; keeps the worked (unrecrystallised) microstructure.7501,100245 HRC31 % IACS

What is EWP (WP)-RX?

EWP (WP)-RX is EWP (WP) heat treated to RX — condition of the electrode zone heated above ~1300–1500 °C in service or by anneal: coarse equiaxed grains, much lower strength and near-zero room-temperature ductility (tip splitting). EWP (WP)-RX has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of tungsten alloy grades. Elongation at break is 0.5% and the elastic modulus is 395 GPa (57.3 Msi). EWP (WP)-RX 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). GF is the default condition FabDigit quotes; RX is available on request or by drawing note.

Limitations

  • Low strength — 420 MPa (60.9 ksi), worse than 100% of tungsten alloy grades
  • Low fracture toughness — 6 MPa·√m (5.46 ksi·√in), worse than 100% of tungsten alloy grades
  • Limited ductility — 0.5%, worse than 90% of tungsten alloy grades
  • Hard to polish — 60/100, worse than 83% of tungsten alloy grades

EWP (WP)-RX properties

Typical room-temperature values for EWP (WP)-RX; 22 are specific to this condition. Other listed values are EWP (WP) reference data and may not represent this condition. Bars are the position among tungsten alloy grades.

Physical3

EWP (WP)-RX 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).

Density19.25 g/cm³0.7 lb/in³
Melting Point (Solidus)3,422°C6,192 °F
Liquidus Temperature3,422°C6,192 °F

Mechanical16

EWP (WP)-RX has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of tungsten alloy grades. Elongation at break is 0.5% and the elastic modulus is 395 GPa (57.3 Msi).

Elastic (Young's) Modulus395 GPa57.3 Msi
Shear Modulus160 GPa23.2 Msi
Bulk Modulus310 GPa45 Msi
Poisson's Ratio0.28
Tensile Strength (Ultimate)500 MPa72.5 ksi
Yield Strength (0.2% offset)420 MPa60.9 ksi
Elongation at Break0.5%
Reduction in Area0.5%
Compressive Strength1,300 MPa189 ksi
Shear Strength320 MPa46.4 ksi
Fatigue Strength (Endurance Limit)160 MPa23.2 ksi
Fracture Toughness (K_IC)6 MPa·√m5.5 ksi·√in
Charpy V-Notch Impact (RT)0.5 J0.37 ft·lbf
Hardness, Brinell330 HB
Hardness, Rockwell C35 HRC
Hardness, Vickers350 HV

Thermal5

EWP (WP)-RX is rated for continuous service to 500°C (932 °F). It conducts heat at 174 W/m·K (100.5 BTU/hr·ft·°F), better than 95% of tungsten alloy grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).

Thermal Conductivity174 W/m·K101 BTU/hr·ft·°F
Specific Heat Capacity132 J/kg·K0.03 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)4.5 µm/m·K2.5 µin/in·°F
Latent Heat of Fusion285 J/g123 BTU/lb
Max Service Temperature (continuous)500°C932 °F

Electrical3

EWP (WP)-RX conducts electricity at 32 % IACS, better than 95% of tungsten alloy grades.

Electrical Conductivity32 % IACS
Electrical Resistivity5.4×10⁻⁸ Ω·m2.13 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is good (65/100), better than 71% of tungsten alloy grades.

Galvanic Potential (seawater, vs SCE)-0.15 V
Corrosion ResistanceGood65/100
Chemical Resistance SummaryResistant to most mineral acids, alkalis and liquid metals at room temperature; attacked by HNO3/HF mixtures, hot alkaline oxidisers (H2O2, hypochlorite) and molten nitrates; oxidises rapidly in air above ~450 °C forming volatile WO3.

Sustainability4

Producing a kilogram of EWP (WP)-RX takes about 380 MJ of energy and emits 25 kg of CO₂ — less than 62% of tungsten alloy grades. Typical recycled content is 20%.

Embodied Energy (primary production)380 MJ/kg163,371 BTU/lb
Embodied Carbon (primary production)25 kg CO₂/kg
Embodied Water300 L/kg35.9 gal/lb
Typical Recycled Content20%

Manufacturability7

EWP (WP)-RX's machinability is not recommended (8/100, worse than 71% of tungsten alloy grades); weldability not recommended (10/100); formability not recommended (2/100).

MachinabilityNot recommended8/100
Machinability Rating (AISI 1212 = 100 %)4%
WeldabilityNot recommended10/100
Formability (cold)Not recommended2/100
Brazeability / SolderabilityFair45/100
PolishabilityGood60/100
Anodizing Responsen/a — refractory metal; electrodes are supplied ground or chemically cleaned, not anodised

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with EWP (WP)-RX

Is EWP (WP) easy to machine?

Effectively non-machinable by turning; shape by diamond/SiC wheel grinding, EDM or laser, always grinding longitudinally on a dedicated wheel with dust extraction.

Can EWP (WP) be welded?

Not a structural weld material — it is the non-consumable electrode; joining W itself requires EB or diffusion bonding because fusion causes recrystallisation embrittlement.

Can EWP (WP) be formed, bent or molded?

Made by powder pressing, sintering and hot swaging/drawing above ~1200 °C; no cold forming — rods snap rather than bend at room temperature.

What surface finishes work on EWP (WP)?

Supplied centreless-ground or chemically cleaned; ball the tip on AC for aluminium/magnesium and re-dress the tip rather than plating or coating.

EWP (WP) 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.

ElementSpec limit (wt %)Nominal
Other elements, totalimpurities per AWS A5.12 / ISO 6848 for WP≤ 0.50.3
Wno intentional oxide additions (green colour code)≥ 99.5 (balance)—

EWP (WP)-RX — frequently asked

What is EWP (WP)-RX used for?

EWP (WP)-RX is typically used for AC TIG welding of aluminum, magnesium welding and general-purpose GTAW. In short: lowest-cost TIG electrode; green-band AC aluminium electrode; no radioactive thorium.

What is the yield strength of EWP (WP)-RX?

EWP (WP)-RX has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of tungsten alloy grades. Strength varies by condition: see the 3 listed tempers.

Is EWP (WP)-RX easy to machine?

Not especially — machinability is rated not recommended (8/100, worse than 71% of tungsten alloy grades). Effectively non-machinable by turning; shape by diamond/SiC wheel grinding, EDM or laser, always grinding longitudinally on a dedicated wheel with dust extraction.

Can EWP (WP)-RX be welded?

Not readily — weldability is rated not recommended (10/100). Not a structural weld material — it is the non-consumable electrode; joining W itself requires EB or diffusion bonding because fusion causes recrystallisation embrittlement.

What surface finishes work on EWP (WP)-RX?

Supplied centreless-ground or chemically cleaned; ball the tip on AC for aluminium/magnesium and re-dress the tip rather than plating or coating.

Can EWP (WP)-RX be formed, bent or molded?

Made by powder pressing, sintering and hot swaging/drawing above ~1200 °C; no cold forming — rods snap rather than bend at room temperature.

What is the maximum service temperature of EWP (WP)-RX?

EWP (WP)-RX 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 EWP (WP)-GF and EWP (WP)-RX?

GF is the default condition — standard stocked condition: centreless-ground bright surface for best current transfer and clean arc starts; keeps the worked (unrecrystallised) microstructure. RX: condition of the electrode zone heated above ~1300–1500 °C in service or by anneal: coarse equiaxed grains, much lower strength and near-zero room-temperature ductility (tip splitting). Yield strength is 750 MPa in GF versus 420 MPa in RX.

Sources

  1. AWS A5.12M/A5.12 Specification for Tungsten and Oxide Dispersed Tungsten Electrodes for Arc Welding and Cutting — AWS (2009)
  2. ISO 6848 Arc welding and cutting — Nonconsumable tungsten electrodes — Classification — ISO (2015)
  3. GB/T 4187 — SAC/ (2017)
  4. ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
  5. Tungsten — material properties and product data — Plansee SE (2023)
  6. CRC Handbook of Chemistry and Physics (thermophysical data for 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.