At a minimum jointing and planing has to be done if you add in resawing,
depending on the thickness of the rough cut stock, you can stretch a bit
more use out of a board.
Tools. Resawing would be a band saw though the job can be done of a table
saw assuming low enough stock. jointing and planing can be done with hand
tools or power jointer and planer.
Pros and cons
Most hardwood suppliers will mill stock for you for an additional charge.
Rough cut stock is cheaper then milled S2S or S4S stock.
Even equipping yourself with hand tools to do the job can, one way or
another, carry a fairly high price tag.
You pretty much have to be going through a large amount of stock to realize
a savings in lumber costs over the cost of the tools to true stock in
anything like a reasonable amount of time.
Milling stock to size, even with power tools, can be a time consuming and
As you noted, 4/4 is usually the thinnest stock you can buy off the shelf.
Seldom will you get really true stock from a supplier. That is, stock with
no warp and all sides are parallel to the others and at 90 degrees to it's
Really trued stock is a dream to work with. Having stock that is exactly X
inches wide and long, all the sides are at Y degrees to their adjoining
sides, and parallel to their opposites, leads to easier assembly with all
the pieces coming together as they should and tighter better looking joints.
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