Long Series 5230T. Used for milling keyways and slots. Bright finish. Flute type: 30 helix. Manufactured to BS 122: Part 4: 1980. Inch Tolerances: Diameter: up to 1/2". Tolerance: +0.0005, -0.0013. Diameter: Over 1/2". Tolerance: +0.0005, -…View more