TECHNICAL SPECIFICATION: Metal. The PRECOIL Manual tang breaking tools are used to break off the tang from an insert so that the fastener can fully pass through, thereby allowing the thread repair insert to accomplish full thread engagement with the male thread and achieve maximum thread strength. It is crucial that the correct diameter for the tang breaking tool is used. When using a manual tang breaking punch to remove the thread repair insert (Helicoil insert), a sharp tap with a hammer will provide the sufficient force needed to remove the tang. HSN CODE: 82034090