You can also use plastic (like pvc, or something similar) rods, available from plumbing or plastic suppliers. The rods are used for welding plastic pipe, etc when they don't want to, or can't glue. I made a dip rod with some gray plastic rod about 4mm - 5mm in diameter, for my 4 reel Kinderman tank, after the disk on the end of the one supplied broke off. I just used a heat gun to soften the rod, bending a 90 degree angle, then doubled it back. Has worked like a charm for 20 some years.