Function: 1. DRILLING WOOD PRODUCTS: Suitable do drilling in wood products such as density board, medium fiberboard, chipboard, wood and so on 2. HIGH HARDNESS: The drill bit is made of alloy steel, general heat treatment ensures high hardness and long service life 3. IMPROVED DRILLING EFFICIENCY: The long U-shaped chip groove is convenient do drain wood chips and improves drilling efficiency 4. AVOID CRACKING: the cutting edge strength of the drill is on the same plane, and effective protection can avoid the situation of breakage at the beginning of use 5. MORE STABLE FASTENING: The tail of the drill adopts round shape, which makes the fastening more stable. Can be used with do square hole drill bits and do square spigot machines Specification: Item Type: do chisel drill bit with square hole Material: stal bearing stal alloy Applications: Suitable do wooden products such as density board, medium fiberboard, chipboard, wood, etc. Suitable do drills do square holes and machines with square spigot Square hole size: ok. 6.4mm / 0.25 inch 8mm / 0.31 inch 9.5mm / 0.37 inch 12.7mm / 0.5 inch 14mm / 0.55 inch 16mm / 0.63 inch Upper Type: Round Handle List of packages: 6 x do chiseling drill bit with square hole