festy steering knuckle pinch bolt question

[cliferton]

OK I was removing the pinch bolts on the lower control arm and one of them stripped. I was going by the transmission removal thread I noticed it said these were special. looks like a standard metric bolt to me. I left it at home today so I have not had a chance to size it up. What is supposed to be special about it. The length of the smooth bore or possibly the diameter of the smooth part? I need this knuckle to get me through 1 more autox then kia knuckles are going on it.
Thanks

[Movin]

I think it is not a hex bolt but a flange bolt and I think it is not standard 8.8 grade but 10.9 Not totally trusting my memory but I think that is the right direction.

[F3BZ]

[Movin]

Wrong wrong and wrong on my part. Anything that would fit the hole standard or better would clamp as well as that bolt.

[WmWatt]

Standard dimension metric bolt from the big box hardware store. "8" is the hardness. Go for "8". I think they are called "shoulder" bolts because of the smooth part. Take the old one with you to check size and thread. Check thread by trying a nut from the bin at the hardware store to fit both old and new bolts. The beveled tip helps it go into the hole easier without damaging the threads. You may not find one with a bevelled tip. Don't force it in. I stick a nail or punch in the hole to line it up before inserting the bolt and it goes in easily that way. Use a torque wrench if you have it. If the nut comes loose you'll get a clunking noise going over bumps as the pin on the control arm rides up and down in the knuckle.

[sketchman]

Nah, those are just partially threaded. Shoulder bolts are different. I think it's the step between the flat and threads that makes it a shoulder bolt. But I'm not exactly sure.

I notice there are no knurls on the replacement OEM ones pic'ed. Wonder why the difference?

[WmWatt]

Thanks for the clarification on "shoulder bolt".
I also suggested using a nut out of a bin but of course the thing to do is just take both nut and bolt off the car.