Science · Level 1 · 121 words
How Sandpaper Smooths Wood
Original passage © Studio AM, written for Fluency.
Sandpaper feels rough because hard grains cover its surface. Each grain acts like a tiny cutting edge. When the paper moves across wood, the grains shave off high spots and leave small scratches. Coarse paper has larger grains, so it removes material quickly.
Fine paper has smaller grains. It removes the deeper marks left by coarse paper and makes the surface feel smoother. A worker often begins coarse and changes to finer paper in steps. Dust can hide scratches, so wiping the wood helps reveal the result. As grains break or fill with dust, the sheet cuts less well and must be cleaned or replaced. Sandpaper does not press bumps flat. It slowly cuts them away until the surface is even.
Source: Written for Fluency. Original passage © Studio AM, written for Fluency.