The plain side bars and bottom bars are 9 mm thick, Top bars on simple frames are 11 mm-14 mm thick (whatever is to hand), cell space sides are 18 mm thick. The bridge plates either side of the cell space are 2 mm thick (some lollipop sticks are ideal for this purpose).
All parts are grooved to accept the edge of foundation and the side bars are drilled for nylon or wire reinforcing.
This simple type of frame is basically a standard B.S. brood frame reduced to 178 mm (7") wide with 19 mm lugs instead of 38 mm.
The type illustrated should be glued and screwed using No 4 x 19 mm Csk Screws and a good quality waterproof wood glue.
The method of construction is not critical... I use a variety of methods according to what materials are available. For instance if I have several full size top bars with broken lugs (or new ones with ugly knots) I re-cut these to suit half width or 1/3rd width frames then use factory made side bars and standard bottom bars cut in half using a razor saw so as not to lose too much in the cutting.
This second type of frame incorporates the cell space for emergence of queens produced by grafting or cell cup cage methods. Notice that the width of most parts is 28 mm, with only the lugs reduced to 22 mm.
The twin top bars of this type are best made from waterproof plywood 9 mm thick (dimensions as plan view in component drawing).
The bottom bar is 9 mm thick, with the ends rebated to give a thickness of 6 mm at the point where the screwing and gluing hold the bar in place, giving good rigidity as well as perfect positioning of side bars.
If a large batch is to be made then assembly time can be reduced and consistency improved by making hardwood components as per the drawing below right.
The choice of wood is unimportant. I have used mahogany from old furniture...
Simply because it was available.
Refer to B.S. Frame Sides for dimensions and drilling layout of the wiring holes.