The rate at which you need to replace the blades largely varies depending on the hardness of the wood you are chipping. The harder the wood, the quicker the blades will need to be replaced.
However, the chipper/mulcher is equipped with twin reversible blades. The reversible blades mean that you can simply switch the blades around when the first set start to dull, so you get a much longer life span on the blades.
We also stock spare blades on our website, should you need to have them replaced.
If you wish to sharpen the blades yourself, this can be accomplished with the use of an oil stone. Simply sharpen the edges of the blades, do not worry about removing any dents or marks.