What causes thread breaks/ frays?
While there is no single factor that can be identified that causes thread breaks, you can narrow down the root of the problem from by following these troubleshooting tips. If the thread is breaking on just one needle, first check to see if the machine is threaded properly. Try loosening the tension slightly Check the needle to be sure it is inserted properly. The needle eye should be facing straight forward. You may want to replace the needle with a new one.