be all thumbs

be all thumbs

To be uncoordinated or clumsy with one's hands. My mother does beautiful calligraphy, but I'm all thumbs—I can barely hold the pen!
See also: all, thumb

be all ˈthumbs

(also be all ˌfingers and ˈthumbs) be unable to hold something without dropping or damaging it; be clumsy: He’s all thumbs when it comes to fixing machines.
See also: all, thumb