Grobet Swiss Pattern File Screwhead With Tang 3 Inch #6 Used for filing slots in small screws. Available in thicknesses ranging from No.1 (thickest) to No.8 (thinnest). Single cut on both edges. Both sides are safe. .018" thick. 25/64" wide. Swiss Pattern files means a type of fine file used for precision filing of jewelry, instrument parts, and dies. It does not necessarily mean that all Swiss Pattern files are Swiss made. Used by Professionals