7PCS Upgraded Four Blade Serrated Drill Bits Hex Shank Eccentric Tip for Tile Brick Concrete Drilling

7-piece upgraded four-blade eccentric drill bit set includes two 5mm, two 6mm, one 8mm, 10mm and 12mm drill bits. Built with durable carbide serrated cutting tip and spiral deep flutes, it delivers fast chip removal and smooth drilling without clogging. This drill set supports dual dry & wet drilling modes: dry drilling works for brick, concrete and timber, while water-assisted drilling is ideal for ceramic tile, marble, glass and metal sheets. Standard hexagonal shank is universally compatible with most electric drills, a practical essential for all household renovation and DIY hole drilling work.Usage InstructionsFirmly lock the hex shank into your electric drill chuck before starting drilling work.Mark accurate hole positions on workpiece surface to prevent shifting during drilling.Use dry drilling method on bricks, concrete and wood without cooling water needed.Pour small amounts of water continuously when drilling tile, stone or glass to cool the bit and avoid cracking.Keep the drill perpendicular to the surface and apply mild steady pressure instead of brute force.Pull the drill out occasionally to clear dust and reduce abrasion; clean and store bits in dry environment after use.