What grit sandpaper to use on aluminum?

Aluminum is a soft, ductile metal that requires careful grit selection to avoid surface scratches or deformation during sanding.

For heavy stock removal—such as smoothing welds, removing deep scratches, or shaping aluminum parts—start with coarse grits (80–120). These grits cut through material quickly but leave noticeable scratches, so they are only for initial prep work. Next, move to medium grits (180–240) to refine the surface, eliminate coarse grit scratches, and prepare the aluminum for further finishing. This stage is critical for achieving a uniform base before polishing.

For finishing and polishing, use fine grits (320–600) to create a smooth, scratch-free surface. For a mirror-like shine, progress to ultra-fine grits (800–1500) or even wet-sanding with these grits—wet-sanding reduces dust and prevents abrasive particles from embedding in the soft aluminum.

Always sand aluminum with light pressure and work your way up from coarse to fine grits gradually. Skipping grit stages will leave deep scratches that are hard to remove later.

Match the sandpaper grit to your aluminum project stage—coarse for shaping, medium for refining, and fine to ultra-fine for a polished finish.