Dormer A100 11/64in HSS Jobber Drill DORA1001164 Dormaer A100 series general purpose HSS jobber drills are suitable for use in the majority of general purpose engineering applications. They have good self-centring capability on a wide range of materials and are suitable for both hand and machine use.DIN338RN BS328 ISO235 Size. 11/64in DORA1001164