Common production suspension materials

[ncoates77]

I am trying to determine whether the welded pressed-steel box-section trailing arms and subframes on an eighties BMW (E30-chassis) would likely be mild steel or not. On the same note, which materials are commonly used on load-bearing members of currently produced mass-production vehicles?

 

[Tmoose]

Secretely i'd guess they were not too exotic, but I'd drill a few 1/8 diameter holes in one, and drill similar holes in a few test pieces of know material. One of those spring loaded center punches makes a poor man's hardness tester for gross measurements.

 

[gdodd]

Not sure about BM's but current sub frames, suspension arms and chassis rails are made from either hot rolled or cold rolled high strength low alloy steels sheet or coil. In addition, such steels can be galvanneal or galvanised pre-coated for corrosion resistance.

Regards