Just ask for drill rod (specify a carbon steel, as opposed to high
speed steel, which you don’t want. Also, an oil hardening steel will
be tougher than a water hardening one, if they have it.) Some of the
shapes of Starret flat ground stock might also work. These are
rectangular rod, but it’s made in widths/thickness as little as a
quarter inch square. thats a fine tool steel for your use. But the
Starret stock is the expensive way to go… Not all machine tool
stores carry these, but the better ones do. If that doesn’t help,
find the MSC web site, and order it from MSC. They carry it.
Peter Rowe