Tungsten Alloy WVMA (Doped Non-Sag Tungsten)
ASTM F288 · also AKS Tungsten
WVMA is potassium-, silicon- and aluminium-oxide doped (AKS) non-sag tungsten wire covered by ASTM F288, in which the dopants form interlocking grain boundaries that resist sag and creep at incandescent temperatures.
Reference datasheet — WVMA (Doped Non-Sag Tungsten) 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 AD-CL condition
WVMA (Doped Non-Sag Tungsten) tempers and conditions
WVMA (Doped Non-Sag Tungsten) is supplied in 5 conditions, soft to hard. AD-CL is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Recrystallised | Condition after flashing/service above ~2000 °C: long interlocked grains give the sag resistance the doping is designed for, but the wire is brittle at room temperature. | 600 | 700 | 1 | 36 HRC | 32.5 % IACS |
Swaged / ground rod | Larger diameters produced by rotary swaging and ground to size — for electrodes, furnace hooks, supports and evaporation sources needing sag resistance. | 1,000 | 1,200 | 2 | 43 HRC | 32 % IACS |
Stress relieved | Wire annealed ~1000–1400 °C in hydrogen to relieve drawing stresses and give straight, spring-free wire for probes, supports and precision heaters. | 1,400 | 1,750 | 3.5 | 43 HRC | 32 % IACS |
AD-CLDefault As-drawn, cleaned (bright) wire | Standard stock condition: cold-drawn doped wire with the graphite drawing lubricant chemically/electrolytically removed — for filament coiling, heaters and probe wire. | 1,900 | 2,200 | 2.5 | 48 HRC | 31 % IACS |
As-drawn, black (graphite-coated) wire | Cheapest form — drawing graphite left on the surface; pick it when the wire will be cleaned, coiled and hydrogen-fired by the user. | 1,900 | 2,200 | 2.5 | 48 HRC | 31 % IACS |
Supply forms, finishes and certifications
Ways WVMA (Doped Non-Sag Tungsten) is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
COIL | Coiled / coiled-coil filament | Supply form |
What is WVMA (Doped Non-Sag Tungsten)?
WVMA is potassium-, silicon- and aluminium-oxide doped (AKS) non-sag tungsten wire covered by ASTM F288, in which the dopants form interlocking grain boundaries that resist sag and creep at incandescent temperatures. It is the standard filament and heating-element wire, drawn to 1900 MPa yield and 2200 MPa tensile with 2.5% elongation, 168 W/m·K, 31% IACS and use to 2000 °C in vacuum or inert gas. Ductility and formability (score 25) are low, it is effectively unmachinable by turning, and oxidation above roughly 400 °C rules out air service. Plain CP tungsten is the alternative where non-sag behaviour is not required. WVMA (Doped Non-Sag Tungsten) has a density of 19.3 g/cm³ (0.697 lb/in³), heavier than 90% of tungsten alloy grades. It melts at 3,422°C (6,192 °F). WVMA (Doped Non-Sag Tungsten) has a yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of tungsten alloy grades. Elongation at break is 2.5% and the elastic modulus is 400 GPa (58 Msi).
What is WVMA (Doped Non-Sag Tungsten) used for?
- Incandescent lamp filaments
- Vacuum tube heaters
- Halogen lamp coils
- Resistance heating wire
Advantages
- High strength — 1,900 MPa (276 ksi), better than 100% of tungsten alloy grades
- Forms and bends easily — 25/100, better than 90% of tungsten alloy grades
- Low embodied carbon — 22 kg CO₂/kg, better than 79% of tungsten alloy grades
- High service temperature — 2,000°C (3,632 °F), better than 76% of tungsten alloy grades
Limitations
- Hard to polish — 55/100, worse than 98% of tungsten alloy grades
WVMA (Doped Non-Sag Tungsten) properties
Typical room-temperature values for WVMA (Doped Non-Sag Tungsten)-AD-CL; bars are the position among tungsten alloy grades.
Physical3
WVMA (Doped Non-Sag Tungsten) has a density of 19.3 g/cm³ (0.697 lb/in³), heavier than 90% of tungsten alloy grades. It melts at 3,422°C (6,192 °F).
Mechanical16
WVMA (Doped Non-Sag Tungsten) has a yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of tungsten alloy grades. Elongation at break is 2.5% and the elastic modulus is 400 GPa (58 Msi).
Thermal6
WVMA (Doped Non-Sag Tungsten) is rated for continuous service to 2,000°C (3,632 °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
WVMA (Doped Non-Sag Tungsten) conducts electricity at 31 % IACS, better than 83% of tungsten alloy grades.
Chemical & Environmental2
Corrosion resistance is good (60/100), better than 50% of tungsten alloy grades.
Sustainability4
Producing a kilogram of WVMA (Doped Non-Sag Tungsten) takes about 380 MJ of energy and emits 22 kg of CO₂ — less than 62% of tungsten alloy grades. Typical recycled content is 30%.
Manufacturability7
WVMA (Doped Non-Sag Tungsten)'s machinability is not recommended (12/100, better than 67% of tungsten alloy grades); weldability poor (15/100); formability poor (25/100).
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 tungsten alloy family
Yield strength against density for every tungsten alloy grade FabDigit runs. WVMA (Doped Non-Sag Tungsten) is highlighted; hover a dot for its name, or open the interactive family chart.
Working with WVMA (Doped Non-Sag Tungsten)
Is WVMA (Doped Non-Sag Tungsten) easy to machine?
Effectively unmachinable by conventional turning; use wire/sinker EDM, grinding with diamond or resin-bonded SiC, and abrasive or laser cutting — never shear recrystallised wire cold.
Can WVMA (Doped Non-Sag Tungsten) be welded?
Fusion welding embrittles by recrystallisation and gas pickup; join by resistance/spot welding, laser microwelding, or braze with Ni, Cu-Ag or Zr-active fillers in vacuum/hydrogen.
Can WVMA (Doped Non-Sag Tungsten) be formed, bent or molded?
Fine wire can be coiled at room temperature; larger diameters and tight-pitch coils must be warm-formed at 300–800 °C over a Mo mandrel that is later dissolved in acid.
WVMA (Doped Non-Sag Tungsten) 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 |
|---|---|---|
| Kretained potassium from K–Si–Al doping, 50–100 ppm; the bubble-forming dopant | 0.01 | 0.01 |
| Siresidual from potassium silicate dopant | 2×10⁻⁴ – 0 | 8×10⁻⁴ |
| Alresidual from aluminium chloride dopant | 2×10⁻⁴ – 0 | 0 |
| Motypical impurity limit | ≤ 0.01 | |
| Fe | ≤ 0 | |
| O | ≤ 0.01 | |
| C | ≤ 0 | |
| W≥99.95 % excluding dopants, per ASTM F288 / GB/T 4181 | balance |
What surface finishes work on WVMA (Doped Non-Sag Tungsten)?
Supplied black (graphite) or electrolytically cleaned bright; hydrogen firing removes carbon, and Ni/Cu/Au plating is used to aid soldering — no anodising, protect from air above ~400 °C.
Equivalent designations
Standards and trade names that resolve to Tungsten Alloy WVMA (Doped Non-Sag Tungsten) in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- F288
- Trade names
- AKS Tungsten
- Similar grades
- GB/T 4181
How much does WVMA (Doped Non-Sag Tungsten) cost?
WVMA (Doped Non-Sag Tungsten) is a high-cost tungsten 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.
WVMA (Doped Non-Sag Tungsten) — frequently asked
What is WVMA (Doped Non-Sag Tungsten) used for?
WVMA (Doped Non-Sag Tungsten) is typically used for incandescent lamp filaments, vacuum tube heaters, halogen lamp coils and resistance heating wire. In short: non-sag doped tungsten wire; standard filament coil wire; highest strength in family.
What is the yield strength of WVMA (Doped Non-Sag Tungsten)?
WVMA (Doped Non-Sag Tungsten) has a typical yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of tungsten alloy grades. Strength varies by condition: see the 5 listed tempers.
Is WVMA (Doped Non-Sag Tungsten) easy to machine?
Not especially — machinability is rated not recommended (12/100, better than 67% of tungsten alloy grades). Effectively unmachinable by conventional turning; use wire/sinker EDM, grinding with diamond or resin-bonded SiC, and abrasive or laser cutting — never shear recrystallised wire cold.
Can WVMA (Doped Non-Sag Tungsten) be welded?
Not readily — weldability is rated poor (15/100). Fusion welding embrittles by recrystallisation and gas pickup; join by resistance/spot welding, laser microwelding, or braze with Ni, Cu-Ag or Zr-active fillers in vacuum/hydrogen.
What surface finishes work on WVMA (Doped Non-Sag Tungsten)?
Supplied black (graphite) or electrolytically cleaned bright; hydrogen firing removes carbon, and Ni/Cu/Au plating is used to aid soldering — no anodising, protect from air above ~400 °C.
Can WVMA (Doped Non-Sag Tungsten) be formed, bent or molded?
Fine wire can be coiled at room temperature; larger diameters and tight-pitch coils must be warm-formed at 300–800 °C over a Mo mandrel that is later dissolved in acid.
What is the maximum service temperature of WVMA (Doped Non-Sag Tungsten)?
WVMA (Doped Non-Sag Tungsten) is rated for continuous use to about 2,000°C (3,632 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between WVMA (Doped Non-Sag Tungsten) AD-CL and WVMA (Doped Non-Sag Tungsten)-RX?
AD-CL is the default condition — standard stock condition: cold-drawn doped wire with the graphite drawing lubricant chemically/electrolytically removed — for filament coiling, heaters and probe wire. RX: condition after flashing/service above ~2000 °C: long interlocked grains give the sag resistance the doping is designed for, but the wire is brittle at room temperature. Yield strength is 1,900 MPa in AD-CL versus 600 MPa in RX.
How much does WVMA (Doped Non-Sag Tungsten) cost?
WVMA (Doped Non-Sag Tungsten) is a high-cost tungsten 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
- ASTM F288 — Standard Specification for Tungsten Wire for Electron Devices and Lamps — ASTM International (2018)
- GB/T 4181 — (Tungsten wire) (2017)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
- Doped (non-sag) tungsten wire and filament data — Plansee / Osram Sylvania / (2023)
- Refractory metal property and eco-property data — Granta/CES-type materials database (2022)
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.