This keenly sharp tungsten carbide file cuts through the toughest “hard casing” like a hot knife through butter, yet leaves a very smooth finish, eliminating the need for progressive filing, reducing the amount of work to bring the edges to polished.
Tungsten files are more costly than a standard file, but the cutting results and longevity can offset the cost. Simply the finest files out there.
Tungsten carbide is more brittle so be sure to remove major burrs with a stone prior to filing and, for goodness sakes, don't drop 'em!
IF you want to spend the minimum time removing the maximum material, these are for YOU. ADVANCED TUNERS ONLY. An inexperienced mechanic can do TONS of damage in an instant.