Titanium Step Drill Bits 3-12mm 4-12mm 4-20mm 2 Flutes Hex Shank for Metal Wood Plastic High Speed Steel 1 Set

Specifications: Product Name: Step Drill Bits Surface Treatment: Titanium Coated Material: High Speed Steel Shank Diameter: 6.3mm / 0.25 inch 3-12mm: Step Quantity: 10 Total Length: 78mm / 3.1 inches Cutting Diameters: 3mm 4mm 5mm 6mm 7mm 8mm 9mm 10mm 11mm 12mm 4-12mm: Step Quantity: 5 Total Length: 70mm / 2.8 inches Cutting Diameters: 4mm 6mm 8mm 10mm 12mm 4-20mm: Step Quantity: 9 Total Length: 71mm / 2.8 inches Cutting Diameters: 4mm 6mm 8mm 10mm 12mm 14mm 16mm 18mm 20mm Package Contents: 3 x Step Drill Bits 1 x Hop-pocket Maintenance Tip: 1.Not for hammer drill. 2.It is recommended to oil the bit before every use. 3.Please drill a smaller hole to make drilling smoother. 4.Please do not set drilling speed too high to avoid damages to cutting edge. 5.The metal sheet on which you want to drill should not exceed 0.38” in thickness. 6.Check the concentricity of the spindle and spring chuck and the clamping force of spring chuck for it may cause the drill bit broken and make drill hole too large.