Metric,- Chromium-plated finish to avoid corrosion,- "SUPER DRIVE" Lobular design with no corners that eliminates stress and provides maximum strength and durability,- Heat-treated alloy steel for maximum resistance and durability,- Made of Chrome Vanadium steel
- Made of high-speed steel that provides better performance and greater service life when using it on machinery ,- High-speed steel provides, compared to carbon steel, higher resistance to friction and torsion