Up to 3 times faster than a standard drill - Flat drill bits are a great accessory for electricians and other installers as well as construction workers. What if they could be even faster and more efficient? With Bosch Tip Technology, this is possible. The Expert SelfCut Speed offers the most advanced designs for flat drill bits. This makes it easy to use and extremely practical for professional users. The patented thread tip from Bosch pulls the flat drill bit into the wood with minimal pressure from the user. This is especially helpful when you need to drill overhead or in tight spaces. The advanced paddle design provides additional speed. The Bosch Expert SelfCut Speed flat drill bit is suitable for softwood boards, chipboards, or particle boards alike. It offers craftsmen efficiency and comfort when they need to drill through holes or blind holes to install cables, dowels, or other hardware. Hex shank for maximum power transfer in standard drill chucks and hex screwdriver chucks. Diameter (D) mm: 40, overall length (L2) mm: 400, shank diameter (d) inches: 1/4.