Guides / Materials

Pure Tungsten, Tungsten Heavy Alloy or Tungsten Carbide: Which Grade for Your Part

September 25, 2026 · Reviewed September 26, 2026

“Tungsten” on a drawing can mean four different materials, and mixing them up is the single most common reason a tungsten RFQ gets quoted wrong or not at all. This guide compares pure tungsten, tungsten heavy alloy and tungsten carbide directly, so you can pick the right one before the drawing goes out.

In short: heavy alloy is the answer when you need density and toughness, pure tungsten is the answer when you need extreme heat resistance, and carbide is the answer when you need wear resistance and hardness. Most machined tungsten parts turn out to be heavy alloy once the actual requirement is examined.

What each material actually is

Pure tungsten is at least 99.95% tungsten, made by pressing and sintering powder, sometimes forged or rolled afterward. It has the highest melting point of any metal and a density around 19.3 g/cm³.

Tungsten heavy alloy is 90 to 97% tungsten held together by a binder of nickel and iron (W-Ni-Fe) or nickel and copper (W-Ni-Cu). The binder is what makes the difference: it turns a brittle material into a tough one that machines like a dense steel. Heavy alloy is ordered to ASTM B777, which defines four classes by tungsten content and density, running roughly 17.0 to 18.5 g/cm³.

Tungsten carbide is a ceramic composite of tungsten carbide grains bonded with cobalt, typically written WC-Co. It is not a tungsten alloy in the metallurgical sense; it is a cermet, and it behaves like one. Density runs 14.5 to 15.6 g/cm³, lower than the metallic grades despite the name.

Tungsten copper, covered in detail elsewhere on this site, is a fourth material worth a one-line mention here: a porous tungsten skeleton infiltrated with copper, used for its conductivity rather than for density or hardness. It sits outside the three-way comparison this guide focuses on.

Density and what it means for part size

Material	Typical density (g/cm³)	Versus lead (11.3)
Tungsten heavy alloy	17.0 to 18.5	50 to 60% denser
Pure tungsten	~19.3	70% denser
Tungsten carbide	14.5 to 15.6	28 to 38% denser

For a shielding or ballast application, higher density means the part can be smaller for the same effect. Pure tungsten and heavy alloy are close enough that the choice between them rarely comes down to density alone; carbide is noticeably less dense and is chosen for hardness, not mass.

Toughness and machinability

This is where the three materials diverge most sharply, and it is usually the deciding factor once density needs are similar.

Heavy alloy’s nickel binder gives it enough ductility to shear cleanly under a cutting tool. Shops describe it as machining like hard gray cast iron: it turns, mills, drills and taps on standard CNC equipment with carbide tooling.

Pure tungsten is brittle at room temperature. A cutting edge tends to fracture the material rather than shear it, which shows up as chipped edges, cracked thin walls and a rougher surface. Shops that cut it well use rigid setups, sharp tools and light finishing passes, and often finish the tightest features by grinding or wire EDM.

Tungsten carbide is harder than almost any cutting tool except diamond. It is not milled or turned after sintering at all. Carbide parts are shaped by diamond grinding, wire or sinker EDM, or machined in the soft, unsintered “green” state before the part is fired to full hardness.

Material	How it’s shaped	Typical tolerance
Tungsten heavy alloy	CNC turning and milling	±0.01 to ±0.025 mm
Pure tungsten	Careful milling, grinding or wire EDM for fine features	~±0.025 mm milled, tighter by grinding
Tungsten carbide	Grinding and EDM (or green-state machining before sintering)	±0.005 mm or better by grinding

Heat and service temperature

Pure tungsten’s main advantage over the other two is service temperature. It has the highest melting point of any metal, which is why it is the default choice for furnace hot zones, heat shields, boats and crucibles in vacuum or inert-atmosphere equipment.

Heavy alloy’s nickel binder limits how hot the part can run before the binder softens, well below pure tungsten’s working range. Carbide’s cobalt binder has a similar limitation, and carbide is rarely chosen for high-temperature service in the first place; it is chosen for wear resistance at more moderate temperatures.

If your application genuinely needs extreme heat resistance and nothing else will do, pure tungsten is usually the only grade that fits, and the machining difficulty is the cost of that requirement.

Magnetic or non-magnetic

This question only applies to heavy alloy, since pure tungsten and carbide are both non-magnetic on their own. Standard heavy alloy uses a W-Ni-Fe binder, which carries mild magnetism from the iron content. Where a part sits near MRI equipment or magnetically sensitive instrumentation, W-Ni-Cu heavy alloy swaps iron for copper in the binder, removing the magnetism at a similar density.

Cost comparison, without prices

Tungsten prices move with the raw material market, so specific numbers age badly, but the ranking between grades is stable:

• Heavy alloy costs the least per finished part in this group, because it machines fastest and with the least scrap risk.
• Pure tungsten costs more, driven by slower cutting, higher scrap rates from chipping and cracking, and more finishing by grinding or EDM.
• Carbide costs the most per feature, since grinding and EDM are inherently slower processes than milling, though small carbide parts can still be economical because they use less raw material.

Decision table

Your part needs	Best fit
Maximum mass in a fixed space (shielding, ballast, counterweights)	Tungsten heavy alloy
Non-magnetic, dense part near MRI or sensors	Heavy alloy, W-Ni-Cu
Service temperature near tungsten’s melting point (furnace hot zones, crucibles)	Pure tungsten
Extreme surface hardness and wear resistance	Tungsten carbide
Fine EDM electrodes or electrical contacts	Tungsten copper (not covered in depth here)

Getting the right grade on your RFQ

The most reliable way to avoid a mismatched quote is to state the actual requirement, not just the word “tungsten.” Tell your shop or sourcing contact whether density, heat resistance, wear resistance or conductivity is what makes tungsten necessary for this part, and let that requirement point to the grade.

When your drawing is ready, send your RFQ and we match it with shops that cut the grade your part actually needs. For a deeper look at what heavy alloy and pure tungsten each allow on the machine, see what each tungsten grade allows. For how the grade choice affects your quote, see what machined tungsten parts cost.

Frequently asked questions

Sources

• Wikipedia - Tungsten
• Wikipedia - Tungsten heavy alloy

Keep reading

• Molybdenum Copper or Tungsten Copper: Choosing a Heat Spreader Material
• Doped Tungsten: Lanthanated and Potassium Doped Grades and Their Parts