Sewing machine thumb screws with slot :   5 pcs per pack

9/64-40 : 9/64" (3.5mm) thread diameter,  40 threads per inch,  Tap #503

Overall length : 17mm,  Thread length : 11mm

Description : 1.  Fits virtually all home and industrial sewing machines

                      2.  Attaches presser foot to foot bar.

                      3.  Attaches folders, binders etc. to base (bed) of sewing machines.