> "What are the advantages of using this type of tool for sanding.....stupid question"
> No,this is NOT a stupid question at all,just needs some clarification for you. Basically,all these mandrels are is a sophisticated lathe pin for spinning shafts and butts. This is a "master" pin,an exact duplicate of the joint you are using. What you do after you choose the particular size/profile,is cut your shaft and butt rings down as close to the carbide as you can get them,then sand the material down flush with the carbide ring. The carbide is simply used for it's resistance to wear from repeated sanding,being the hardest metal available other than an exotic. This process is one of the factors in having truly interchangable shafts,since all your shafts are sanded to the same dimension. Different sizes are used for pre/post finish. They can also be ordered to have a specific taper,such as a mandrel for blending joint collars to a butt with a tapered stainless joint. There has also been debate as to whether a 1/2 long carbide is long enough,some recommend a 1.000 collar. At the 250.00 a set that was mentioned earlier,these are a steal,most cost close to double that. Tommy D.