Feature: 1. Titanium plating to reduce friction and heat. 2. Made of fine quality high speed steel, wear resistant, not easy to rust, has a long service time. 3. Flute design provides faster, smoother and cleaner cutting. 4. Different specifications can meet different drilling requirements. 5. The aluminum box can accommodate and protect the drill bits. 6. Suitable for cutting holes in various materials, including steel, brass, wood, plastics, etc. 7. Center punch accurate locator, anti-slip and crooked. Specification: This is a set of step drills made of high speed steel 4241. Different specifications can meet different drilling requirements. The aluminum box can accommodate and protect the drill bits. Features: Titanium plating to reduce friction and heat. Made of fine quality high speed steel, wear resistant, not easy to rust, has a long service time. Flute design provides faster, smoother and cleaner cutting. Different specifications can meet different drilling requirements. The aluminum box can accommodate and protect the drill bits. Suitable for cutting holes in various materials, including steel, brass, wood, plastics, etc. Center punch accurate locator, anti-slip and crooked. Specifications: Material: high speed steel 4241 Quantity: 5pcs step drills+1pcs center punch 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 1/2" (6 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2" Shank diameter: 1/4" to 1-3/8": 3/8in 3/16" to 7/8": 3/8in 1/4" to 3/4": 3/8in 1/8" to 1/2": 1/4in 3/16" to 1/2": 1/4in Package size: 150 * 125 * 43mm / 5.9 * 4.9 * 1.7in Package weight: 550g / 1.2lb Packing List: 5 * Step Drill 1 * Center Punch 1 * Aluminum Box Package List: 5 * Step Drill 1 * Center Punch 1 * Aluminum Box