Well I noticed my RS' rear passenger 19mm sway bar end link bolt sheered off below the sway hole -- no idea what caused it. Prothane is sending a free replacement after I sent them a picture & receipt. They said the bolts are NOT made in China, but here...

It's always something with cars...

 

After all the advertising hype, one needs to realize that very often after market parts are not subjected to the same quality controls of OEM parts . Being that the bolt was not made in China is not an indication that it was specked properly, or that it was made to specs, or that the batch was quality tested. The main drive of most businesses is the bottom line, so cost cutting is important.

 

To make sure you get a really up to spec fasteners, try ARP or FASTENALL. Two of the more trusted names out there... but you will pay for quality, (and safety).

For sway bar end links, you are looking at a minimum Grade 5 fastener, preferably a Grade 8 for all the fasteners associated with the bar, and it's mounts.

 

woh,,, liberty you been 4x4in in the camaro?

 

Grade 5 (Metric 8.8) is more than enough for most suspension parts. Grade 8 (Metric 10.9) is not always best.

 

The only thing I can think of that would cause a swap bar bolt to break would be if it was over tighten to start with or if the sway bar was bent.

On the other hand, defects in cold formed bolts are not uncommon. If the form tooling wears or is not set correctly it can cause a fold near the head and if the thread rolls wear they can form stress cracks in the thread. Here in the US the higher the grade the more testing is needed per lot, odds are higher grade = less defects. If the bolts are made over seas and no one is policing the company the grade marks mean almost nothing. Last time I tested a grade 8 bolt from a hardware store it failed the pull test about where a grade 4 should fail. I also noted the grade 8 bolts where selling for less per pound then I could buy the raw material for in bulk. I am afraid to think of how low the base bolt would measure or what the heck its made from.

 

Since I know you all want to see the evidence...

 

If I am seeing that right it looks like it broke off right near the head that would indicate a manufactures defect. Normally they break at the bottom a in the thread area. Lower grade bolt don’t get a lot of tests but on a mid to upper grade bolts we will test say 5 bolts per 10,000 pcs, we will pull them apart, if the head pops off one of the 5, like yours, they are tossing 10,000 bolt in the scrape bin. (I have not worked for a bolt manufacture since 96 so don’t hold to those numbers)

Looks like you ran the car awhile with it broken. You must not push the car hard. When I break a sway bar link I normal know within a few hundred yards where it broke

 

The right side of the photo is where the sway bar would connect, the left side is above the body mount. I can see how much was sheered off when the replacement gets here, but yea its on the head side.

 

Comparo