RX8 hitch - custom or not?

[Dean!]

Re: RX8 hitch - custom or not?

So how did you bend that hardened steel ??

I like it !

[Fair!]

Re: RX8 hitch - custom or not?

So how did you bend that hardened steel ??

The only "hardened" steel I worked with was in the factory bumper structure. I didn't have to bend any of that, just drill three thru-holes for mounting my custom hitch mount.

edit: a plasma cutter would have made quick work of those holes.

The steel I used in my hitch mount is (low) carbon steel, probably 1018 or 1020. It has a tensile strength and hardness that is about half of the "alloy" steels, like those in the 4000 series. "Carbon" steel is very malleable and easier to work with than alloy steels. It is also not effected by welding (localized embrittlement) like most other alloy grades.

This is why so much is built with carbon steel. It can still plenty strong but is easier to bend, weld, and buy. It can be hardened by heat treating, but often isn't. In the highest strength applications where weight is very critical, you use alloy steel... or other, more costly materials like titanium, carbon fiber, aluminum, etc. Most of these materials ratchet the cost up, and some have even more drawbacks and fabrication concerns.

Oh yea - I bent the low carbon steel with a vice, a big hammer, and a lot of swinging - and I did it cold. A real fab shop would have used a metal brake or heat + a fixture to bend this stuff, and that would have looked a little cleaner and been a lot easier. It is easier to bend steel when heated to higher temperatures, but that can change the metal properties if care is not used.