These drill bits are designed for 8.5mm mushroom dowels, and are suitable for high speed electric drills. If you are using a rechargeable drill, please use our no.34 bits with a hex shank.

D, the diameter is 8.5mm,  the overall length is 75mm; the Flute Length is 40mm, and the shank size is 6.5mm

These high speed drill bits go deeper than our other bits, which can be handy if your bark is thick.