This Pencil Polishing Brush is great to use for polishing and finishing step. Used widely in aerospace, plant maintenance, foundry, automotive, metal fabrication and shipyards. Material: Stainless steel. Wheel Brush Diameter: 5mm (0.20\" approx.). Shank Length: 40mm (1.57\" approx.). Shank Diameter: 3.17mm (0.12\" approx.).