Linear Motion Guide, FEYRINX 2PCS 6mm x 150mm (.236 x 5.9 inches) Case Hardened Chrome Linear Rail Rod Shaft for 3D Printer, DIY, CNC - Metric h8 Tolerance

Thank you for contacting me with your inquiry. We double-checked it, and yes, it was our error. Its straightness number should be less than 5 meters per 100 millimeters. This information has been updated on our website.

I haven't seen any that have been drilled and threaded that aren't custom length OEM parts, but I had no trouble drilling and tapping them with a cordless drill; the outside layer is hardened, so grinding it off first makes it much easier.

If you want, you can thread them all day with a lathe, but first you must remove the chrome (chemically or with abrasives) and anneal the section of the rod that needs to be threaded. If you don't have silicon carbide or diamond, you'll have to grind the threads.

That would depend on the diameter and length of the rods you ordered, as well as how they're mounted on your cart: if the rods are attached to the cart by their ends and a single wheel in the middle, you should expect some nasty destruction before it's all said and done. If, on the other hand, you can keep all the strains in shear by placing your rod mounts right next to the wheel(s), you'll have a much better chance of getting it to work. However, unless you have a very good reason to use highly precise, extremely straight, and finely polished rods as axles, it would be a travesty to use rods like these for such a purpose. Hint: There are very few good reasons in the world for doing so. You could probably get away with it if you found a nasty stick of galvanized round rod in the alley behind your local hardware store.