Kendo 13-Piece Spade Drill Bit Sets, Alloy Steel Paddle Flat Bit With, 1/2" HIGH QUALITY MATERIAL: Constructed from Alloy steel with fully heat-treated for durability and hardness above carbon steel, the head with the polished surface is made to ensure long life and high wear resistance. FEATURE: The cutting edge with double-side cutting spurs of high quality grabbing wood and carving it away, creating beautiful holes with reduced breakout.Accurate drilling on Wood, Fiberglass, Plastic, PVC (Polyvinyl Chloride) . VERSATILE: Includes 13 high-quality spade drill bits, Size 1/4", 5/16", 3/8", 1/2", 9/16", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8", 1-1/2" .Come with a nylon storage pouch for easy storage and organization. QUICK-CHANGE HEX SHANK: The hex shank is 1/4 with groove for reducing slipping and preventing falling off, universal for the most drill driver tool of brands in the markets. KENDO Your Professional Partner: If you are not satisfied with our product for any reason, we offer 100% refund or replacement.