Made of alloy steel, fully heat-treated, its durability and hardness are higher than carbon steel, and the head has a polished surface to long service life and high wear resistance. Includes 13 high-quality spade drill bits in sizes 1/4 inch, 5/16 inch, 3/8 inch, 1/2 inch, 9/16 inch, 5/8 inch, 3/4 inch, 7/8 inch, 1 inch, 1-1/8 inch, 1-1/4 inch, 1-3/8 inch, 1-1/2 inch. Comes with storage box for easy storage and organization. The with high-quality double-sided cutting spurs grips the wood and carves it , creating beautiful holes and reducing breakage. Precision drilling in wood, fiberglass, plastic, PVC (polyvinyl chloride). QUICK CHANGE HEX HANDLE: The hex is 1/4, grooved to reduce slipping and prevent falling off, universally used for most of drill tools on the market. Color: silver Material: alloy steel Package Contents: 13-Piece Spade Drill Bit Sets 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.