These are the top of the line, ultra-fine Hard Arkansas Stones made by Norton and used by professional gunsmiths, pattern makers, wood workers - anyone who wants a super-smooth finish on cutting tools, gouges; for accurizing, trigger work, hard fitting, etc. The 'Premium' designation means these stones are made from selected, finest quality, hard, Ozark Quartz. They show the minimum in variations within each stone and are carefully checked for consistent hardness. A must for truly precision parts fitting and sharpening. SPECS: Ship Wt.1/2 lb. *As with all natural products, sizes
shown are nominal and may vary. METRIC: 1'=
2.5cm.