The Thread Knife is a spare part that is found on some sewing machines and is used to cut the thread after a seam has been sewn. It is typically located near the needle and works by sliding over the edge of the fabric to trim the thread.
The Thread Knife is typically made of metal and is designed to be durable and long-lasting. It is usually adjustable, so that it can be positioned at the correct distance from the needle to ensure that the thread is cut cleanly and at the right length.
If the Thread Knife becomes dull or damaged, it can result in ragged or uneven thread ends, which can be unsightly and may even cause the thread to become tangled or break. In such cases, it may be necessary to replace the Thread Knife with a new one.