Rod
Rod turns up in 2 fields: welding, fiber optics. Here is what it means to the people in each one.
Rod in welding
Shop word for a stick welding electrode, as in burning rod or a box of 7018 rod.
Flux-coated consumable electrode for SMAW, sold in fixed lengths such as 14 inches and diameters like 3/32, 1/8 and 5/32 inch, with its classification printed near the grip end. Welders burn rod, run rod and argue about rod angle, and a rod with damp or chipped flux gets tossed. Rod also loosely means TIG filler wire in straight lengths, and a rod burner is a self-mocking name for a stick welder.
"Grab me a can of eighth-inch rod from the oven and a fresh grinding disc."
Rod in fiber optics
To push a stiff fiberglass duct rodder through a conduit to prove the path or to carry a pull line through.
Duct rodders are long fiberglass rods spooled on a reel cage, stiff enough to push through hundreds of feet of conduit. Crews rod a duct to find blockages, to see if a path is clear, or to tie on mule tape and drag it back for the cable pull. Some rods carry a tracing conductor so a locator can find where a buried duct goes.
"Rod the north duct first, if it's crushed under the driveway we'll have to use the spare."