Thread is drawn from the top of the machine down through the material and needle plate by a needle. The needle reaches its lowest position and begins to rise. With the needle under the needle plate, the feed dogs travel under the needle plate from back to front rising as the needle rises. As the needle rises to "loop lift", the hook moves behind the needle to pick up the thread loop wrapping the thread around the bobbin thread. The needle rises tightening threads into a knot inside the fabric forming a lock-stitch.