DIN 1.6759 (G18NiMoCr 3-6) Cast Steel 1

[1MarcoD]

I'm looking for a US equivalent of the above for spec'ing purposes, but it doesn't seem to exist. Some places give ASTM A487 Grade 6 as an equivalent but there are a number of problems with that:

The ASTM grade has a lower yield (655 compared to 700 MPa)
The ASTM grade has a huge permissible variation in Carbon content (0.05-0.38 compared to 0.17-0.22%)
The ASTM spec is cast steel for pressure vessel components whereas this application is for truck suspension components, e.g a knuckle.

On this basis I don't see ASTM 487 Grade 6 being equivalent, but I don't know what is. Anyone got an idea of an equivalent, or alternatively knows a good high-strength US cast steel spec with good fatigue properties for a heavy offroad truck?

 

[Flesh]

I would recommend reviewing ASTM A148 and ASTM A732. Alloy SAE 8630 is fairly common for cast suspension componentry.

 

[1MarcoD]

Thanks. Of course it's the usual problem of how close it has to be to be "equivalent" without giving the supplier too much latitude. I was actually looking at ASTM A958 SC8620 and up before I read your post, which is probably the closest in chemical comp, but 8620 wouldn't have the strength and 8625 and 8630 have a higher C content so I don't know if the fatigue properties would be the same. Time to make an engineering decision. I'm familiar with them from gear work so it's not totally foreign.

Thanks for your reply - it's good to know I'm looking in the right area.