How do the grinders work?

[dark3000x]

Im trying to grind a wep but I don't understand how it works. I used a board to make C grinders and i got items like Grinder C+1, Grinder C+8 etc... what do the different numbers mean?

[BlueFire2k5]

Your grinding success has to do with the quality of your grinder (1-10) and your luck. Take a look here > http://www.psupedia.org/index.php?title=Weapon_Grinding for more information including tables.