明·吴承恩《西游记》三十一回：“俗语云：尿泡虽大无斤两，秤砣虽小压千斤。”

秤砣虽小压千斤，秤砣看来一小块却能压住千斤之重。比喻外表虽不引人注目，实际很起作用。

for want of a nail the battle was lost; apparently insignificant details can have a large impact; although small, a steelyard weight may tip a hundred pounds (idiom)