Alfa 12 SS CCA Chopper/Grinder Attachment Stainless Steel, # 12 Hub.
The #12 worm is marked by a 1/2 inch shaft (the long cylindrical extension--measured at its square tip).
Included in item 12 SS CCA:
Stainless steel grinding cylinder head, pan, ring, worm, stainless steel knife, chopper plate with 1/4″ holes, chopper plate with 5/16″ holes, 3/4″ plastic stuffing tube, and plastic stomper.
12 SS CCA fits most mixers, grinders, food cutters and power unit hubs that are #12 standard / Hobart compatible.