Not all sandpaper is the same. The abrasive grain determines how long it lasts, how aggressively it cuts and what it costs. The two most common materials are aluminium oxide and ceramic grain.
Aluminium oxide
The most common grain type. Stable, broadly applicable and affordable. Aluminium oxide fractures under pressure into smaller sharp particles, keeping itself sharp. Suitable for wood, metal and paint. The default choice for general use.
Ceramic grain
Significantly harder and longer-lasting than aluminium oxide. Ceramic grain has a crystal structure that creates micro-fractures under high pressure — so the cutting surface always stays sharp. As a result, the product lasts three to five times longer under intensive use.
The downside: ceramic sandpaper is noticeably more expensive. The premium pays off in professional use where speed and lifespan matter. For occasional use, the benefit is smaller.
When ceramic?
- Intensive use on hard materials (steel, titanium, hardened metals)
- High sanding pressure with power sanders
- Situations where downtime for tool changes is costly
- Long sanding runs on belt sanders
When aluminium oxide?
- Hand sanding and light machine sanding
- Softer materials such as wood and fillers
- When a wide range of grit sizes is needed
- Cost-conscious work