I bought this Dado set on line from a woodworking supply outlet and when i recieved it i went to install it in my Dewalt DW744 contractor table saw. My saw has a 5/8`` arbour but European blades have a 30mm or 1-1/4`` bore, Dewalt overcomes this by supplying an outside blade washer with a 30mm protrusion which locks into the blade bore. I had two options when i bought this Dado set, i could have bought one with a 5/8'' bore or a 30mm bore. As all my table saw blades have a 30mm bore i assumed the Dado with the 30mm bore would fit my saw. Sadly it didn`t, the two outside blades went on fine but when i tried to install some chippers between them they just sat down on the blade arbour. The outside blade washer`s protrusion isn`t long enough to support the chippers, obviously i didn`t try to turn on the saw with this configuration. In my own defence this was my first Dado set so my knowledge of them is limited. Freud makes some assumptions with the instructions on this set, i just don't understand how a saw with a 5/8'' arbour can be fitted with a Dado set with a 30mm bore. I can't speak for other saws that are manufactured for the European market but i'm fairly sure that they all have 5/8'' arbours with outside blade washers with 30mm protrusions. Unless Freud are selling adaptors with a 5/8'' bore with a 30mm outside diameter, i don't understand why they are selling the 30mm bore Dado sets. This problem won't be an issue for Americans or Canadians as 5/8'' bore tablesaw blades and Dado sets are standard in those countries.