For those of you ... who like me, don't always like working with plywood because of it's sizing issues, there now it hope.
To refresh your memory, as you know none of the plywood you purchase is dimensionally the the thickness size you purchase. For example 3/4 inch plywood is almost never 3/4 inch thick. The reason for this is the standards adhered to by the plywood manufacturers industry states, in essence, that a 3/4 inch thick plywood can NEVER exceed 3/4 inch thickness. Since all plywood is manufactured green (i.e. it still contains a lot or water and will shrink as it dries) this means that the dimensional thickness will be less that the generic name it is given. That is that 1/4", 3/8", 1/2" 3/4" will all be somewhat LESS thick that what they are called. This means, working with plywood can be a challenge, despite all the other benefits that plywood has, like strength, flexibility lamination of hardwoods such as Oak, Rosewood, Maple, Cherry etc. all have a thin veneer of that hardwood laminated to an otherwise softwood plywood base.
So ... if you are wanting to make a nice Oak Book Case, and Oak Plywood is on special at your local lumber store, you run on out, pick up a few sheets and get ready to start making some cuts. Then you realize that none of the 3/4" Oak Plywood sheets are actually 3/4" thick, but are somewhat less ... now what ...
Any woodworker worth his dust, will know a book case needs shelves, and that shelves need dados to sit in. We all know the best, easiest and safest way to cut dados is with a router but who makes an undersized bit that will cut dados in one pass ... well the answer is Rockler.
Rockler has an entire series of undersized router bits, signed for plywoods
Copyright Colin Knecht