Diamond Brand Rubbing Brick / Silicon Carbide Sharpening Stone (manufactured in China), used for heavy-duty grinding, deburring, and coarse-sharpening of metal tools, blades, or stone/concrete surfaces. Key Features • Material: Silicon carbide abrasive • Brand: Diamond Brand (鑽石牌) • Primary Use: Coarse shaping, edge repair, and smoothing rough surfaces or tools How to Use • Preparation: Soak or lubricate the stone with water or honing oil depending on manufacturer guidelines. • Technique: Rub the tool or surface against the abrasive side using steady, even pressure and a consistent angle. • Cleaning: Rinse away metal filings and slurry with water after use Large / Heavy Duty Size: 9" x 3" x 2" (approx. 225 x 75 x 50 mm) — Primarily intended for heavy masonry rub down, masonry edges, and flat surface smoothing