stainless uprights?

[Tommy Cookers]

the ordinary steel that you initially mentioned will do just the same job as 4130 (at 10-20% of the cost ?)

these are not aviation-type steady loads, IMO you cannot design to stresses that will take 4130 close to its elastic limit
(only if so designing would the ordinary steel need to be thicker (than the 4130) to avoid going beyond its elastic limit)
those spaceframe race cars even in F1 were made from the cheaper material for this reason

anyway, best wishes for your project !

[marcush.]

So, turned out there was much more to this than I originally thought! Galling wasn't of any importance, the only thing threaded into the upright was ever going to be the speed sensor.

Many thanks for all your input! I will now acquire me some 4130 sheet.

kind regards,
Tom

I d propose get a Sample of4130 and try anything Tools You have available making an Impression...
You will Soon realise the Common stuff just will Not work at all .Hi grade Materials Need pro Tools and pro approach .I would strongly advise to do yourself a favour and Keep it simple.
There is a reason for Aerospace materials ....You Would Not be able to achieve your Goals eG meet all requirements.if them requirements are not clearly defined no Justication for exotic materials !why making your Life harder with no Need to do so?