These T1 HSS Cutters are 17% Tungsten Steel.
T1 HSS is the best tool steel for high impact and high wear resistant. It is why it is the primary material used in industrial planer blades.
The T1 HSS cutters are primarily used for hollowing. They can be used on captive boring bar systems and hand held tools with a screw. They can also be used as a scraper.
The large cutter size is: 1-3/4″ x 3/4″ x 1/8″