... PLUGS PRODUCTION ON HIGH EFFICIENCY High quality plug cutter for wood in different types on high ... working efficiency.Diameter for plug(metric):6,8,9,10,12,14,15 ... ,16,20mmDiameter for plug(inch): 1/4", 5/16", 3/8", ... 8mm diameter round straight shankSurface treatment: Bright finished or Black-oxidedHardness: HRC44-48Package: double blister ,single blister, skin ...