Waterjet Cutting Tungsten, Tungsten Carbide, and Heavy Alloy (W-Ni-Fe)

Tungsten carbide runs around 1400-1800 Vickers, harder than hardened tool steel and approaching some ceramics, which means conventional cutting tools cannot touch it; you grind it or EDM it. Pure tungsten is extremely dense and brittle, prone to cracking and to a ductile-to-brittle transition that makes it crack-sensitive at room temperature. Tungsten heavy alloy, W-Ni-Fe, binds tungsten powder with a nickel-iron matrix and is denser than lead, used for counterweights and radiation shielding; it is tough but very dense. Abrasive waterjet cuts all three because the erosive process is indifferent to hardness, only slower as hardness rises, and it applies no thermal shock to crack the brittle carbide or pure tungsten. Where a saw blade or endmill is hopeless and a torch would shatter the part, the cold abrasive stream grinds a path through. This makes waterjet a go-to for profiling carbide blanks and sectioning tungsten that cannot be cut any other practical way short of EDM or diamond grinding.

Be realistic: tungsten and its carbide cut slowly, sometimes very slowly, because they are both extremely hard and extremely dense. A waterjet might cut tungsten carbide at a fraction of an inch per minute on thicker sections, far slower than steel, and pure tungsten and heavy alloy are also slow due to their density. This is genuine machine time, and garnet consumption is continuous, so the cut is not cheap. That said, the alternatives are often worse or impossible. Wire EDM cuts conductive tungsten and carbide and gives a finer finish, but it is also slow and limited in thickness, and it only works on conductive grades. Diamond grinding is precise but cannot rough out a profile efficiently. Waterjet's niche is profiling and sectioning tungsten and carbide where its speed, however modest, beats the alternatives for bulk material removal, especially on non-conductive tungsten compounds or thicker sections that challenge wire EDM.

The waterjet edge on tungsten carbide is rougher and shows more striation than on metal because of the slow cut, and there is a real risk of edge chipping or microfracture on the brittle material, particularly at the bottom of the cut where the jet exits. Skilled shops manage this with reduced jet pressure on entry and exit, careful pierce strategy, and sometimes a sacrificial backing to support the brittle exit edge. Even so, expect to leave generous stock. Because tungsten and carbide parts demand precision and fine finishes for their tooling, wear, and shielding roles, the waterjet is almost always a roughing or sectioning step. Leave substantial grind stock, on the order of 0.030 inch or more, and finish by diamond grinding or EDM. The waterjet's contribution is getting a near-net profile out of an otherwise nearly uncuttable material, not delivering a finished surface. For final tolerances and edges on carbide, grinding and EDM remain the finishing processes.