Steel structured is preserved. No metal is taken away. Very good durability and self sharpening. 

Allow to make sharper bevels than hot rolling, but with reduced durability. 

Allow to make the sharpest bevels. Those « Razor » blades are used on vertical tillage machines. 

Some discs can be made without a bevel when there is no need to cut or penetrate the soil deeper. 

Can be paced on the inside or the outside depending on how the disc work. 

Can be paced on the inside or the outside depending on how the disc work. Self sharpening effect. 

 Mostly used on flat discs when mounted perpendicular to the ground.