This drill set includes 3 sizes: 4-12mm, 4-20mm, and 4-32mm. Comes with a portable fabric bag.

Step drills for metal: The two-flute design provides faster, smoother drilling. Equipped with low pressure, the set can cut through wood, plastic, and other surfaces with a thickness under 5mm. Step cone drills designed for precision drilling of holes in various sizes from 4mm up to 32mm in diameter, optimal speed and accuracy.

Titanium High-Speed Steel Drills Usage: classic high-speed steel with titanium coating for proven capability and durability when drilling holes in plastic, aluminum, copper, and many other types of sheet metal. Titanium drills are particularly suitable for processing copper and aluminum pieces / mold steel / spring steel / cast iron pieces / iron and other metal materials.

Quick assembly: 1/4 \"(6.35mm) hex shank works with most drills or drills with a 1/4 \" chuck