The "P" in sandpaper grit stands for "P-grade," which is a standard defined by the Federation of European Producers of Abrasives (FEPA). This designation is used to classify the coarseness or fineness of the abrasive grains on the sandpaper. The "P" grading system ensures a consistent and predictable level of abrasiveness.
Here’s a quick overview of the P-grade system:
- **P40-P50**: Coarse grits used for heavy material removal and rough shaping.
- **P60-P80**: Medium grits used for general sanding and shaping.
- **P100-P180**: Fine grits used for smoothing surfaces and removing small imperfections.
- **P220 and above**: Very fine grits used for final finishing and polishing.
The P-grade system is essential for standardizing sandpaper, making it easier to select the appropriate grit for specific tasks and ensuring consistent results across different manufacturers and products.