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Can You Machine Tungsten? What Each Grade Allows and Where It Stops

September 20, 2026 · Reviewed September 26, 2026

Yes, you can machine tungsten. The honest answer has a condition attached: it depends on which tungsten you mean. Tungsten heavy alloy turns and mills on ordinary CNC machines. Pure tungsten can be machined but punishes careless setups. Tungsten carbide is not really machined at all after sintering. It is ground.

This guide explains what each grade allows, which features cause trouble and how to write a drawing that shops can quote without padding the price for risk.

Three materials sold as “tungsten”

Before any talk of feeds and tools, check the material callout on your drawing. Buyers often write “tungsten” when they mean one of three quite different materials.

Pure tungsten is at least 99.95% tungsten, made by pressing and sintering powder and sometimes forging or rolling the result. It has the highest density of the group, about 19.3 g/cm³, and the highest melting point of any metal. It is used where heat matters most: furnace heat shields, crucibles, boats and some electrodes.

Tungsten heavy alloy is 90 to 97% tungsten held together by a binder of nickel and iron or nickel and copper. The binder turns a brittle material into a tough one. Density runs from about 17.0 to 18.5 g/cm³ depending on tungsten content. It is ordered to ASTM B777, which defines four classes by tungsten content and density. Heavy alloy is the usual material for radiation shielding, balance weights and counterweights.

Tungsten copper is a porous tungsten skeleton infiltrated with 10 to 30% copper. It conducts heat and current and resists arc erosion, so it is used for EDM electrodes, welding electrodes, electrical contacts and heat spreaders.

A fourth material, tungsten carbide, is a ceramic made of tungsten carbide grains in a cobalt binder. It shares the name but not the process. It is covered briefly at the end.

Machining tungsten heavy alloy

Heavy alloy is the easy case. Shops often compare it to hard gray cast iron. It produces short chips, holds a good surface finish and can be turned, milled, drilled, bored, tapped and threaded on standard CNC equipment.

What changes compared with steel:

Tooling. Carbide inserts and end mills are standard. The tungsten grains are abrasive, so tools wear faster than on steel of similar hardness.
Weight. A heavy alloy part weighs more than twice the same part in steel. Large blanks need proper lifting and rigid workholding, and a thin-walled part can move when it is released from the fixture.
Magnetism. The W-Ni-Fe grades are slightly magnetic. If the part must be non-magnetic, for example near an MRI system or a sensor, the drawing should call for W-Ni-Cu.
Chips and dust. Shops collect heavy alloy chips separately. They have scrap value and the fine dust needs to be controlled. None of this affects you as a buyer, but it is one reason not every shop wants the work.

On turned and milled heavy alloy parts, tolerances of ±0.01 to ±0.025 mm are common. Threads, O-ring grooves and bores are routine. If your part is a shield, weight or collimator, heavy alloy is almost always the right starting point.

Machining pure tungsten

Pure tungsten is where most trouble starts. At room temperature it is brittle. It only becomes ductile at a temperature well above what a part sees on a machine, so the cutting edge tends to break material out rather than shear it.

That shows up as:

Chipped edges and corners, especially where the tool exits the cut.
Cracks in thin walls and thin sections, from clamping force or cutting force.
Rough surfaces, because material fractures instead of forming a clean chip.
Fast tool wear, from the hardness and abrasiveness of the material.

Shops that cut pure tungsten well work around these problems. They use rigid setups, sharp carbide tools, light finishing passes and exit chamfers that protect edges. Some warm the workpiece to reduce brittleness. Many finish fine features by grinding or wire EDM rather than trying to mill them.

Realistic expectations for pure tungsten:

Milled and turned features at around ±0.025 mm, tighter by grinding.
Holes drilled with care, but small deep holes are risky. EDM drilling is often the better route.
Walls thinner than about 1 mm are a warning sign. Ask the shop before you fix them in the design.
Sharp external corners chip. A small chamfer or radius on the drawing lowers the scrap rate and the price.

If your application does not need the heat resistance of pure tungsten, switching to heavy alloy is the single biggest change you can make to cost and lead time.

Machining tungsten copper

Tungsten copper is the easiest of the three to cut. The copper phase makes the material behave more like a hard brass or bronze. It takes fine detail well, which matters for EDM electrodes and contacts.

The main points to watch are burrs from the copper phase and consistency of the material itself. Ask for the tungsten and copper ratio on the drawing, such as W70Cu30 or W80Cu20, because it changes density, conductivity and wear.

Features that raise the price or the risk

Across all grades, a handful of features decide whether a tungsten part is routine or difficult.

Feature	Heavy alloy	Pure tungsten
Thin walls under 1 mm	Possible with care	High risk of cracking
Sharp outside corners	Fine	Chip easily, add a chamfer
Small deep holes	Drilled normally	Often EDM drilled
Fine threads	Routine	Risky, may be ground or avoided
Large flat faces	Milled or ground	Often ground

If a feature on your drawing appears in the right-hand column, expect fewer shops to quote it and higher prices from those that do. That is not a reason to avoid pure tungsten when you need it. It is a reason to design for it.

Blanks and near-net shapes

Tungsten is expensive and slow to cut, so the starting shape matters. Mills that make tungsten can press and sinter blanks close to the final shape. A near-net blank leaves only a few millimetres to machine, which saves material, machine time and tool wear.

For one-off parts, shops usually cut from standard bar or plate. For quantities in the dozens and above, ask whether a near-net blank makes sense. The mill may charge for pressing tooling, but on the right part that cost pays back quickly.

Tolerances you can put on the drawing

The numbers below are typical, not promises. They assume a rigid setup and a shop that cuts the grade regularly.

Heavy alloy, turned or milled: ±0.01 to ±0.025 mm on most features.
Pure tungsten, milled or turned: around ±0.025 mm, tighter on selected features by grinding.
Tungsten copper: ±0.01 to ±0.02 mm is common.
Tungsten carbide, ground: ±0.005 mm or better.

As with any material, tolerance only what matters to function. On tungsten, each unnecessary tight tolerance costs more than it does on steel, because inspection and scrap are more expensive.

What about tungsten carbide?

Sintered tungsten carbide is harder than almost any cutting tool except diamond. General machine shops do not mill or turn it. Carbide parts are made in three ways: machined in the soft green state before final sintering, ground with diamond wheels after sintering or cut by wire and sinker EDM.

If your part is carbide, say so clearly in the RFQ so it goes to shops with grinding and EDM capacity rather than to heavy alloy turning shops.

How to get a useful quote

A good tungsten RFQ answers the questions a shop would otherwise have to ask:

The exact grade. Pure tungsten, heavy alloy by ASTM B777 class, W-Ni-Cu if it must be non-magnetic or tungsten copper by ratio.
A STEP file and a PDF drawing with tolerances, finish and any edge breaks.
Quantity and repeat volume. It decides whether a near-net blank is worth it.
Material source. Whether the shop buys the blank or you supply certified material.
Tests and paperwork. Material certs, density test or radiographic inspection if your customer needs them.

The decisions that follow the grade are laid out in our guide on how to machine tungsten.

When you send your RFQ, we read the drawing and match it with up to three shops that cut that grade at that size. If you are still deciding on a grade, check the grade and density table. If the price is the open question, see what machined tungsten parts cost.

Frequently asked questions

Can you machine tungsten on a normal CNC mill or lathe?

Tungsten heavy alloy, yes. It turns, mills, drills and taps on standard CNC machines with carbide tools, much like hard cast iron. Pure tungsten can also be cut on standard machines, but it chips and cracks easily, so shops run light cuts and often finish fine features by grinding or wire EDM.

Why is pure tungsten so hard to machine?

Pure tungsten is brittle at room temperature. It only becomes ductile well above room temperature, so a cutting edge tends to break material out instead of shearing it. That causes chipped edges, cracked thin walls and a rough surface unless the setup is rigid and the cuts are controlled.

What tolerance can a shop hold on tungsten heavy alloy?

On turned and milled heavy alloy parts, ±0.01 to ±0.025 mm is common. Tighter tolerances are possible on selected features by grinding. The shop that quotes your part confirms what it can hold on your geometry.

Is tungsten carbide machined the same way?

No. Sintered tungsten carbide is too hard to mill or turn with normal tools. It is shaped by diamond grinding and EDM, or machined in the soft green state before sintering. Most carbide parts go to grinding shops, not general machine shops.

Sources

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