Tungsten Alloy EWLa-1-SR (Stress relieved)
Heat-treated state
AISI/SAE AWS A5.12 EWLa-1 · GB GB/T 4189 WL15 · ISO 6848 WL15
Use the rod stress-relief annealed after swaging for long electrodes and automatic feed fixtures needing the best straightness and dimensional stability, accepting yield down to 550 MPa.
Values for the SR condition
Other EWLa-1 tempers and conditions
EWLa-1 is listed in 3 conditions; see the grade overview at EWLa-1.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Use the rod stress-relief annealed after swaging for long electrodes and automatic feed fixtures needing the best straightness and dimensional stability, accepting yield down to 550 MPa. | 550 | 750 | 4 | 40 HRC | 30 % IACS |
Chemically cleaned (as-swaged, black) finish rod | Choose the economical as-swaged rod that is only acid-pickled after swaging for cost-sensitive manual welding; the surface is rougher and diameter tolerance wider, at about 1000 MPa tensile. | 800 | 1,000 | 2 | 46 HRC | 29 % IACS |
GFDefault Centerless ground / polished finish rod | Pick the usual stocked condition — centerless ground bright rod with high diameter accuracy and concentric clamping — for automated welding and precision manual TIG at 1100 MPa tensile. | 850 | 1,100 | 2 | 47 HRC | 29 % IACS |
What is EWLa-1-SR?
EWLa-1-SR is EWLa-1 heat treated to SR — use the rod stress-relief annealed after swaging for long electrodes and automatic feed fixtures needing the best straightness and dimensional stability, accepting yield down to 550 MPa. EWLa-1-SR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 4% and the elastic modulus is 390 GPa (56.6 Msi). EWLa-1-SR has a density of 19.1 g/cm³ (0.69 lb/in³), heavier than 52% of tungsten alloy grades. It melts at 3,410°C (6,170 °F). GF is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Good corrosion resistance — 70/100, better than 88% of tungsten alloy grades
- Ductile — tolerates forming and impact — 4%, better than 80% of tungsten alloy grades
Limitations
- Low strength — 550 MPa (79.8 ksi), worse than 89% of tungsten alloy grades
- Hard to polish — 60/100, worse than 83% of tungsten alloy grades
EWLa-1-SR properties
Typical room-temperature values for EWLa-1-SR; 22 are specific to this condition. Other listed values are EWLa-1 reference data and may not represent this condition. Bars are the position among tungsten alloy grades.
Physical3
EWLa-1-SR has a density of 19.1 g/cm³ (0.69 lb/in³), heavier than 52% of tungsten alloy grades. It melts at 3,410°C (6,170 °F).
Mechanical16
EWLa-1-SR has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 4% and the elastic modulus is 390 GPa (56.6 Msi).
Thermal5
EWLa-1-SR is rated for continuous service to 500°C (932 °F). It conducts heat at 165 W/m·K (95.3 BTU/hr·ft·°F), better than 69% of tungsten alloy grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).
Electrical3
EWLa-1-SR conducts electricity at 30 % IACS, better than 64% of tungsten alloy grades.
Chemical & Environmental2
Corrosion resistance is very good (70/100), better than 88% of tungsten alloy grades.
Sustainability4
Producing a kilogram of EWLa-1-SR takes about 380 MJ of energy and emits 24 kg of CO₂ — less than 62% of tungsten alloy grades. Typical recycled content is 20%.
Manufacturability7
EWLa-1-SR's machinability is not recommended (10/100, better than 52% of tungsten alloy grades); weldability not recommended (10/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EWLa-1-SR
Is EWLa-1 easy to machine?
Grind with diamond or SiC wheels only, taking the tip longitudinally along the axis to stabilise the arc; EDM is also possible. Conventional turning, milling and drilling are not feasible.
Can EWLa-1 be welded?
Not used as a structural weld material; in service it is the non-consumable AC/DC GTAW electrode. Where a joint is needed, use vacuum electron-beam welding or Ni/Cu-base vacuum brazing, and expect a markedly brittle joint.
Can EWLa-1 be formed, bent or molded?
Fully brittle at room temperature — no cold bending or straightening. Shaping is done at the mill by powder pressing and sintering followed by rotary swaging or drawing at 1200–1600 °C; no forming at the user end.
What surface finishes work on EWLa-1?
Standard supply is chemically cleaned black surface or centreless-ground bright finish. Grind the cone angle to suit the current type — a 20–30° sharp point for DC, a small flat or blunted/balled end for AC — and avoid transverse grinding marks.
EWLa-1 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 |
|---|---|---|
| La2O3ISO 6848/GB/T 4187 WL15, gold tip; AWS EWLa-1 0.80–1.20 % (WL10) | 1.3 – 1.7 | 1.5 |
| Other impurities (total)total impurities: Fe, Mo, Si, Ca, Al, Ni, etc. | ≤ 0.2 | — |
| W≥ 98.30 % | balance | — |
EWLa-1-SR — frequently asked
What is EWLa-1-SR used for?
EWLa-1-SR is typically used for AC/DC TIG welding, aluminum and stainless welding and automated GTAW. In short: most versatile AC/DC electrode; non-radioactive general purpose; long tip life.
What is the yield strength of EWLa-1-SR?
EWLa-1-SR has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 89% of tungsten alloy grades. Strength varies by condition: see the 3 listed tempers.
Is EWLa-1-SR easy to machine?
Not especially — machinability is rated not recommended (10/100, better than 52% of tungsten alloy grades). Grind with diamond or SiC wheels only, taking the tip longitudinally along the axis to stabilise the arc; EDM is also possible. Conventional turning, milling and drilling are not feasible.
Can EWLa-1-SR be welded?
Not readily — weldability is rated not recommended (10/100). Not used as a structural weld material; in service it is the non-consumable AC/DC GTAW electrode. Where a joint is needed, use vacuum electron-beam welding or Ni/Cu-base vacuum brazing, and expect a markedly brittle joint.
What surface finishes work on EWLa-1-SR?
Standard supply is chemically cleaned black surface or centreless-ground bright finish. Grind the cone angle to suit the current type — a 20–30° sharp point for DC, a small flat or blunted/balled end for AC — and avoid transverse grinding marks.
Can EWLa-1-SR be formed, bent or molded?
Fully brittle at room temperature — no cold bending or straightening. Shaping is done at the mill by powder pressing and sintering followed by rotary swaging or drawing at 1200–1600 °C; no forming at the user end.
What is the maximum service temperature of EWLa-1-SR?
EWLa-1-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.
What is the difference between EWLa-1-GF and EWLa-1-SR?
GF is the default condition — pick the usual stocked condition — centerless ground bright rod with high diameter accuracy and concentric clamping — for automated welding and precision manual TIG at 1100 MPa tensile. SR: use the rod stress-relief annealed after swaging for long electrodes and automatic feed fixtures needing the best straightness and dimensional stability, accepting yield down to 550 MPa. Yield strength is 850 MPa in GF versus 550 MPa in SR.
Sources
- AWS A5.12/A5.12M — Specification for Tungsten and Oxide Dispersed Tungsten Electrodes for Arc Welding and Cutting — AWS (2009)
- ISO 6848 — Arc welding and cutting — Nonconsumable tungsten electrodes — Classification — ISO (2015)
- GB/T 4187 / GB/T 4189 — SAC (2017)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
- Tungsten electrode (WL15 lanthanated) product data — Plansee / (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.