A silver paperclip lies diagonally on a plain white background, casting a subtle shadow.

A paper clip is a length of stiff steel wire bent into three flat, nested loops to hold sheets of paper together when they are inserted between the loops. The wire is a 1-mm-diameter steel cylinder that is 10 cm long. It is bendable in the fingers but stiff. The first loop is a smooth, U-shaped turn to the right that starts 2 cm from the outermost end of the wire. The second loop is a U-shaped turn to the left that starts 3 cm farther along the wire and has a diameter just small enough to fit snugly within the first loop. The third loop is another U-shaped turn to the right that starts 2 cm beyond and has a diameter just small enough to fit snugly within the second loop (as well as the first). The wire in each inner loop touches and runs parallel to the outer loop that wraps around it. All three loops lie in the same plane, and pushing them out of that plane just enough to slide several sheets of paper between them makes the paper clip act like a spring and squeeze the sheets together. Ver mais