5pcs High Speed Steel Step Drill Bit Set Spiral Groove Round Shank Twist Drills Drilling Tool

This is a set of step drills made of high speed steel 4241. Different Specifications:s can meet different drilling requirements. Features: Made of fine quality high speed steel, wear resistant, not easy to rust, has a long service life.  Double groove design for faster and smoother cutting.  Different Specifications:s can meet different drilling requirements.  Suitable for workpiece with hardness is less than 25°, such as carbon steel, iron plate, aluminum plate, pvc plate, wood board and so on. Specifications: Material: high speed steel 424;  Color: yellow;  Quantity: 5pcs;  Size: 1/4" to 1-3/8" (10 steps): 1/4", 3/8" 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8";  3/16" to 7/8" (12 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8";  1/4" to 3/4" (9 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4";  1/8" to 1/2" (13 steps): 1/8", 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2";  3/16" to