Barbara, This is commonly referred to as a "thread fray" or "fraying of the thread". An embroidery thread is comprised of two smaller threads twisted around each other. So what you're experiencing is one of the two threads is breaking where as the second one is still hanging on. This can be caused by several things... A bent or compromised needle Needle rotation may be rotated too far A burr or scratch along the thread path including the needle eye, needle plate, rotary hook, bobbin basket, retaining finger, etc.. A damaged or compromised hook point - from something like a broken needle Hook timing may need to be reset Needle case could be off center Needle case could be loose in any direction Do a little trouble shooting first. Change to a brand new needle and make sure the needle rotation is straight forward. Try sewing on different needles-move the spool of thread to different needles. Try sewing on a different spool of thread. Try sewing at slower speeds. Verify your needle plate is centered with needle. Verify your needle is centered with the bobbin post. Feel free to ask any questions pertaining to the above. Ed Orantes -----Original Message----- From: amayausers-bounce@xxxxxxxxxxxxx [mailto:amayausers-bounce@xxxxxxxxxxxxx]On Behalf Of Avalon Embroidery Sent: Thursday, December 15, 2005 12:43 PM To: amayausers@xxxxxxxxxxxxx Subject: [amayausers] Re: needles and thread breaks on nylon jacket Judy I'm getting "partial" shredding breaks......where it appears the inner core of the thread usually stays intact, but the outer "shell" gets all knotted up in the needle case area... ----- Original Message ----- From: OnleeJudy@xxxxxxx To: amayausers@xxxxxxxxxxxxx Sent: Thursday, December 15, 2005 10:31 AM Subject: [amayausers] Re: needles and thread breaks on nylon jacket Hi there. A couple of things to try...more backing, as nylon is very light, and sew slow....and depending on the type of thread breaks (clean breaks or shredding breaks), check needle alignment, and add or subtract MT. BEST WISHES!