Description Description Alpha ThunderMax Step Drill Spiral Flute 4-20mm Metric 9 Steps 4, 6, 8, 10, 12, 14, 16, 18 & 20mm 8mm Hex Shank Bulk - 1 piece convenient plastic pack Self-Starting Split Point removes the need for a pilot hole Tempered Black Finish maximises lubricant hold, therefore assisting chip flow & heat dissipation 2 flute design for smooth cutting Laser etched hole ø Corrosion resistant finish 3 flats on shank, prevents slippage in chuck -- Ideal for: Non-ferrous metals, sheet metal and plastic up to 3mm thick. Stainless steel up to 1.5mm thick. Suits: Non-hammer action portable power drills. Cutting Speed: 400 – 1,500 RPM. View AllClose