Tungsten carbide
An extremely hard material used for cutter inserts. It slices braided line cleanly where softer steel crushes and frays it.
Braid is woven from fibres that are strong in tension and slippery. An ordinary steel cutter pushes them apart rather than through, so you get a crushed, frayed end that will not pass through a hook eye. Tungsten carbide is hard enough to shear the fibres instead.
Good pliers use replaceable carbide inserts, which is worth checking, because the cutters are the part that wears out first while the rest of the tool is still fine.
The same material shows up in line clippers and braid scissors. If you fish braid and your cutter frays it, that is the tool telling you it is not carbide.
Carbide is hard and therefore brittle. Cutting wire leaders, split rings or hooks with the same edge you use for line will chip it, and a chipped carbide cutter is done. Keep a separate cheap pair for cutting metal.
Cut braid with the very tip of the carbide edges, not the middle. It concentrates the force and gives you a clean end.
Related terms
Where this comes up
The guides that use tungsten carbide and show it on real gear.
Tungsten carbide is one of 206 terms in the glossary.
Browse the full fishing glossary