broca helicoidal central
/ˈbɾoka ˌelikoɪðˈal θentɾˈal/
n
English: solid center auger bit · 单螺旋木工钻头
Significado：Bit made up of a central shank encircled by a twist; it is very durable and especially designed for making deep holes.
English: solid center auger bit · 单螺旋木工钻头