Yep but it's not rusty.
Once they've rusted into the bushing, how do you remove them? Upper a-arm bolts rusted in bushing! Chemicals, sawzall, fire??????
And that's for a short one! I cannot imagine the price of the lowers and uppers in the rears. wow. Just looked up the prices on the rear suspension bolts. Big bolt on the bottom a-arm: 29.67 Top bolt (hub shock swaybar): 93.37 Ouch! But I'm sure they come in a pretty yellow and black box.
Yeah not looking to buy new because they are so expensive and screw the boots price one of the suspension brackets.
You might want to explore one of the kits from Eastwood for media tumbling small parts. I have one and used it for bolts in similar shape to what you have. I also didn't want to send my original bolts out so this method worked pretty good, not perfect but close. I just put them in the tub and let it run overnight. They have several models and are approx. $150 as I recall. They also have a liquid that you put into the media that helped so if you go this route get that as well.
I have a tumbler, I'm not concerned with cleaning or striping it's replating. I have not had good luck painting hardware. I doesn't last. I guess I could try paint and a flat clear on these bolts..
Hydrogen embrittlement is probably not a significant concern but this is a function of the plating process used, skill of the operator etc, because it determines how much hydrogen evolves during the plating process as well as the time taken to achieve the plating thickness. Ie a high efficiency bath will evolve less hydrogen and plate faster resulting in less hydrogen diffusion into the parent metal. Baking the part in an oven allows the hydrogen to diffuse out of the parent metal. A quick search on the net found that baking the part for 22+ hours at 220 degrees Celsius was required for 50 Rockwell c hardness. You could do this in a home style oven. See "ASTM B 850-98 (2009), Standard Guide for Post-Coating Treatments of Steel for Reducing the Risk of Hydrogen Embrittlement" for timings. Note that you should test this first, as elevated temperatures may cause discolorisation of the plated part, particularly is oils from skin or plating solutions are on the part. If discolorisation occurs an inert atmosphere maybe required during the baking, bit difficult, or an acid clean.
