[Titanium Coating]These twist drill bits are crafted from high-quality HSS material and coated with long-lasting titanium, ensuring that the cutting edges remain sharper for a longer period to meet all your requirements. [Advantage]With a fully ground spiral groove design, these drill bits minimize friction and heat, enabling a cooler and faster drilling action. [Enhanced Efficiency ] Our drill bits feature a pointed central serration, greatly improving chip evacuation, thereby increasing overall drilling efficiency and making the process smoother and quicker. [Applications]Whether you are working with a thin board, wood, aluminum alloy, plastic, or engaged in groove processing, our twist drill bit set is the perfect tool for the job. Colour:Gold Material:Metal Size:3mm, 4mm, 5mm, 6mm, 6.5mm, 8mm Package Contents: 6x Spiral Saw Drill Bit 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.