1. Drilling can be started without -drilling. Drilling speed is fast and friction is extremely low. 2. It is generally applicable to all kinds of metals, glass and hard plastics. 3. It is suitable DIY and general construction and engineering. 4. Use with needle or low-speed electric drill ( to impact drill). 5. Application: High speed steel drill bit set for wood, plastic and aluminum. Ideal for DIY, home and general /engineering use. Type: Twist Drill Bit Uses: drilling holes made of aluminum, iron and other materials. Specifications: 1.5mm x 16, 2.0mm x 16, 2.5mm x 15, 3.0mm x 10, 3.2mm x 10, 3.5mm x 8, 4.0mm x 8, 4.5mm x 3, 5.0mm x 3, 5.5mm x 2, 6.0mm Material: steel colour: Black yellow Package Contents: 1 set x Twist Drill Bit (99pcs) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.