[MATERIAL]6PCS HSS TWIST DRILLS are made of high-speed steel titanium-plated material; 5PCS MASONRY DRILLS are made of carbed , tail is made of 1045 steel; 5PCS WOOD WORKING DRILLS are made of 1045 steel. [16PCS THREE TYPES OF METRIC DRILL SIZE]HSS TWIST DRILL size: 2cm, 3cm, 4cm, 5cm, 6cm, 8cm; MASONRY DRILL size: 4cm, 5cm, 6cm, 8cm, 10cm; WOOD WORKING DRILL size: 4cm, 5cm, 6cm, 8cm ,10cm. [EFFICIENT DRILLING]: Twist bit sets feature a fully ground helical flute design for fast particle removal, reduced friction and heat for faster, cooler drilling performance. [WIDELY USAGE] drill edge allows faster penetration, and one set of tools can be used in metal, construction, and woodworking industries to solve various problems. [WHAT EACH DRILL DOES]HSS Twist Drill Bits for all common sizes of wood/cast iron/aluminum/plastic/fiberglass; Masonry Drill Bits have excellent hole-drilling alloy drills for easy Masonry drilling; Wood Working Drill Bits use Point, these specially designed bits are specifically designed to reduce chipping. Material: Metal colour: Gold+Silver+Black Package Contents: 6 x HSS Twist Drill Bits (2mm-8mm) 5 x Masonry Drill Bits (4mm-10mm) 5 x Wood Working Drill Bits (4mm-10mm) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.