This is the sort of bench I use. It has no joints. It is firmly screwed and glued together and is made mostly of " two by four " planed soft wood with a chipboard top and bottom.

The bench may seem a bit high but it is beter to get used to this than have to stoop more than necesary. I am 5ft 10" tall and so taller or shorter workers might alter the overall height by about half the difference between their height and mine!!!

I used to use softwood planks for the top but found that 3 layers of 18 mm chipboard ( Strongly glued together ) made a firmer flatter worksurface. The front apron is better made of hardwood ( my present one is Ash ) but the rear one can be anything handy. The top is a piece of hardboard lightly pinned in place and I replace mine about once every 2 years.

Use plenty of glue in the construction and I would use 6 mm diameter by 75 mm long countersunk screws to construct the frame and attach the top. I countersink the screws well in the frame and counter bore them into the top a bit.