Hand saws come in two tooth shapes. Most of what can be bought today are made for cutting across the fibers, such as cutting to length.
Saws for cutting with the grain have chisel-like teeth and are called rip saws. Hacksaw teeth have this shape, but are not large enough for serious wood work.
Carpenters' handsaws were made as crosscut or rip saws. I don't know if Japanese saws are readily available in rip configuration. If they are, in pulling them, they need to be at an angle to the wood the makes the teeth enter the grain at about 45 degrees and exit the fibers at their ends. //// ---->
Western style handsaws should enter the cut in the same orientation, but you will be pushing, instead of pulling.
Crosscut saws do not rip well at all.
I have 25 or more handsaws--crosscut, rip, back saws, dovetail saws, compass saws and a keyhole saw. I sharpen and set them myself.
Without getting into the world of handsaws or spending much money, your best bet is probably to get the coarsest hack saw blade you can find and never use it for metal.