Carbide

• Notes
  • Sanding Silicon carbide
    • Every “ordinary” sandpaper is made using either Silicon Dioxide (SiO2) or (more expensive) Aluminum Oxide (Al2O3).

Mohs hardness is about 9.5 for Tungston Carbide (WC) (give or take 0.05 depending on composition), about 9.0 for Al2O3, and 7.0 for SiO2. Which means neither of the usual sandpapers are able to work as abrasive for WC

You need something with a hardness above 9.5 for being able to scratch/abrase WC, which only leaves SiC (9.6) and diamond (10.0), or Boron Nitride (BN) (not available as sandpaper, more expensive than gold, and poisonous).

SiC sandpaper costs about twice as much as Al2O3 here, and the price of diamond sandpaper is decidedly in the two-digit currency per sheet range (so not really a practical option). Your mileage might vary.

SiC is just about hard enough for WC, but don’t expect it to last long.

• Carbide