What's the difference between "drill rod" and "plated steel rod"?

[Robotics Guy]

What's the difference between "drill rod," like this: Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies, and "plated steel rod" like the stuff at Lowes?

Would one be better than the other to use for rails?

[cmnewcomer]

Drill rod is high in carbon and is intended to be hardened but it doesn't have to be. It is rated such as W (water), O (oil), and A (air) for how you indend to quench it during the hardening process. It is a littler tough to machine but still does well as it is in it's soft state so to speak.

The metal at Lowes is most likely a low carbon metal such as 1018 with a protective coating to retard corrison. It can not be hardened and the protective coating would make it a poor candidate for case hardening if necessary.

Best Regards.

Carl

By the way, drill rod is ground so it has closer tolerances than the plated material. So it may be a better choice if you're looking for accuracy even if you don't intend to harden it.

[gmfoster]

Drill rod will normally be a lot closer to nominal in tolerance..

[Robotics Guy]

Thanks for both your replies! It sounds like I should go with drill rod, since it has higher tolerances.

How hard would it be to drill holes through drill rod? Would this be possible to do with a drill press?

[SmoggyTurnip]

Drill rod is very easy to machine. Holes are easily drilled through it.

[ViperTX]

For rail usage....I would not use either and would instead use Thomson 60 linear race shafting.