Expandable toolbox

An expandable toolbox, comprising:

• a first box body comprising a first pivot part and a first engagement part arranged away from the first pivot part;
• a second box body comprising a second pivot part pivotally disposed on the first pivot part along an axis, so that the second box body pivots between a closed position and an expanded position with respect to the first box body;
• when the second box body is at the expanded position, the second box body and the first box body are arranged in an open and flat shape;
• the second box body further comprising a first sliding part disposed on two sides thereof;
• a third box body comprising a second engagement part and a second sliding part, the second sliding part slidably disposed on the first sliding part, so that the third box body slides between a retracted position and an expanded position with respect to the second box body;
• and
• a fastener configured such that, when the second box body is in the closed position and the third box body is in the retracted position, the fastener is engaged with the first engagement part and the second engagement part to retain the third box body relative to the first box body, wherein the first box body and the third box body cooperatively define an outer enclosure of the expandable toolbox, and wherein the second box body is enclosed within the outer enclosure.