I avoid ACE butter bolts at all costs. 

Try McMaster Carr.  Chances are you can find the exact size, grade and finish you desire.  Personally I wouldn’t go to NC, because the clamping force will be different at the same torque.  Also the minor diameter of the fastener is a little smaller on a NC fastener so it won’t be as strong.

They have every flavor of fastener you can think of.  Or just order up the AMK kit for your suspension.

Mcmaster

https://www.mcmaster.com/

Use the stuff that comes with the replacement parts you buy or buy all new from AMK. With AMK, its one stop shopping and you get the correct bolts that are supposed to be installed. Comes in a bag marked for purpose, no guessing involved.

Possible thread derailment...
Anybody know where to buy ARP by size instead of application?

McMaster used to carry ARP as their “extreme” 180,000+ PSI fasteners  but I noticed they don’t carry them anymore.

TKOPerformance wrote:

NEVER replace factory hardware with parts store hardware.  You wold not believe the amount of engineering that goes into factory hardware.  Everything comes into play from material to thread count to size to whether the bolt has a shoulder or not, and if so how much.  The only time I replace factory hardware is with either ARP stuff for engine builds or AMK stuff for restoration purposes.  Those are about the only two sources I trust.  If I knew the original design specs for the hardware I could confidently buy from say McMaster-Carr, etc., but the problem is that I don't.  There are markings that can tell you grade, etc., but if the bolts are available through AMK I'd feel infinitely more confident buying through them.  I mean, its the suspension, not like the hardware's holding on a fender or something innocuous.  If that fastener fails its going to be bad, possibly catastrophic, potentially fatal. 

And, FWIW, fine thread hardware is very different from course thread and you shouldn't as a general rule replace fine thread with course, regardless of grade.  A fine thread bolt and a course thread bolt torqued to the same spec do not produce the same clamp load because the surface area of contract and the ramp angle of the threads are so different. 

Please read: https://www.hemmings.com/blog/2013/11/22/tech-101-identifying-and-replacing-automotive-hardware/

There is no such thing as "parts store hardware".  Hardware is designed and sold by specification, not whether it comes from the "parts store". 

Most hardware to come from the factory is grade 5 even today.  If meets the design specifications and there is really no need to change it. Yellow zinc chromate Grade 8 hardware, which is what I use, exceeds grade 5 in shear and tensile strength.  The coating is the best you can get for protection.  I realize this is over kill just like using the AMK hardware but after removing so many crap bolts and screws I don't mind.. Also realize that when you buy those kits you are really paying for packaging and piece of mind.  The do sell the highest grade, but you can find the same by just shopping by the specifications.  It doesn't matter if you buy hardware from mcmaster, grainger, fastenal, amazon, or home depot as long as the specifications meet your needs  You shouldn't mix different types of hardware and you shouldn't step down your hardware.  In other words don't replace a grade 5 bolt w/ a grade 2 And don't use a grade 8 bolt w/ a grade 5 nut..

As far as all the engineering that went into the hardware I agree with you but not b/c of what you said.  We're talking 1960's Detroit.  They made millions of these cars.  It was all about the bottom dollar.  Hardware selection had nothing to do w/ performance and everything to do w/ cost savings. Imagine just the lower control arm: 2 bolts per car, 2 million cars made, that 4 million 3/8-24 hex head cap screws.  What about 1960's automobiles makes you think they were doing anything other than chasing the bottom dollar.  Unibody  = cheap.  

To answer my own question... I suspect the fine thread used in many of the suspension parts has more to do w/ making it easier to set the torque w/ all the rubber bushings.

I went to a higher grade and a better protective finish.  The only thing I'm ordering that is vehicle specific are the upper control are nuts which I believe are deformed thread. I replaced the 7/16-20 with 7/16-14, the 3/8-24 with 3/8-16 and the 1/2-20 with 1/2-13.  I could have either stayed w/ grade 5 clear zinc hardware, fine thread or gone with the grade 8 course thread.  I prefer the better hardware.  I'll adjust the torque specs if necessary. I upgrade hardware and save a buck from having to buy non stardard hardware.
 

Last edited by TremendousWand (6/14/2018 7:05 PM)

Exactly which bolts do you want to replace?

If you are not happy with ACE hardware's prices then find another vendor. Fastenal is a pretty big name for hardware that you may find local. You shouldn't pay much more for NF over NC hardware in my opinion. I agree that Mcmaster Carr will have any bolt you could want but you will have to factor shipping into your bottom line. Otherwise talk to local body shops or repair facilities and find out where they are getting their hardware from. My take on the whole bolt thing is unless you are an engineer with equipment to test fasteners how can you be sure you are getting what you are paying for anyway. Go with grade 8 hardware of the same design and you should be fine in my opinion. I just wouldn't start subbing hex head bolts where flanged bolts etc were originally on things that articulate or move.

MS wrote:

Exactly which bolts do you want to replace?

I replaced all of the hardware in the front suspension with grade 8 yellow cromate hardware, same style, size, and length.  It seems like all the hardware in the suspension is fine thread (UNF).  It was 50% more getting the same hardware in UNF vs UNC not to mention I would have to order it. I'm sure they had their reason but none of this stuff is going into a blind hole or in any situation where thread engagement is a concern.  

From what I read, a fine thread gives you better shear and tension strength over course hardware of the same material due to more surface area and a larger minor diameter.  This would make sense as it would have allowed ford to use lower grade hardware and reduce cost.

Since I'm upgrading the to grade 8 hardware this will greatly exceed the original hardware even with the course threads.  Main this is the coating.  I was amazed out just how bad all the original hardware had corroded.  I get 60 years old hardware won't look like new especially after decades of exposure to weather but no way in hell was I going to use factory replacement hardware after taking off the original stuff.

I would stick with the fine thread stuff. Clamp force is greater per torque and they don't vibrate loose as easy. I typically use air frame bolts which are more precise and better quality in general and they are sized a little different. They are available in more clamp lengths so they can fit and line things up better. That also means they have a shorter thread length so you don't have all that extra thread. I usually get them from Pegasus Racing or Baker Precision.

TremendousWand wrote:

TKOPerformance wrote:

First, yes, there is parts store hardware.  Sure, its marked grade 5, grade 8, etc., but where does it come from?  How do you know it really meets that grade?  Most of that stuff comes from China, and the stuff I've seen those guys pull would make your head spin.  I've seen Ford parts in Ford boxes, with Ford part numbers on both, that I promise you were never made by Ford.  I've seen spoofed versions of Ford's IDS software so good that it prompted you to log onto Ford's site and update it, at which point Ford locked the software making it unusable since they knew it wasn't real.  So, no, I'm not willing to risk my life that a bolt from Home Depot, etc. that's yellow zinc plated and marked as grade 8 really is.  I'm not wiling to risk my $30k+ car on it either.

Second, it was 1960's Detroit, and I still promise you that an engineer was involved in specifying every bolt, washer, and nut on these cars.  I've read an entire book on the subject from the time period written by one of the guys who founded AMK.  Cost is always a consideration in anything mass produced.  BUT, its not the only consideration.  Unibody design for example was revolutionary when it was used in the 1950 Hudson Hornet.  Those made great race cars because they were both lighter and lower to the ground without a frame.  Today no cars have frames; in fact really next to nothing does except a few SUVs and trucks. 
 

Grainger, McMaster, Fastenal, Autozone, Homedepot, Summit Racing, Oriley, NAPA, etc are all distributors.  They don't make this stuff.  Even the stuff that is branded under their namesake is just purchased licensing rights. If buying something from one particular place gives you peace of mind then good.  Otherwise, regardless of manufacturer, reseller, or place of origin if something is sold as being to a certain specification then you should feel comfortable believing that it is to that specification.  This logic is a result of marketing more than anything else.  Same reason people still buy the 10 dollar tyelonol bottle when the CVS brand is 2 dollars and they are the exact same thing.  I guess we each have our own hangups.  If you'll excuse me I need to go buy a 7 dollar gallon of organic milk.

 

The logic is absolutely not the result of marketing.  Its the result of experience.  It also has nothing to do with cost.  I really don't care about a $2 bolt vs. a $5 bolt.  If the $2 bolt works I'll gladly use it.  There's a vast difference in the sources mentioned in terms of who I'd trust as well.  Home Depot is not in the hardware business.  They are in the home improvement business, and the revenue generated from selling bolts and nuts is a tiny, tiny fraction of their revenue on a yearly basis.  The only reason they even carry that stuff is to try to be a one stop shop, which is how they've been putting the local hardware stores out of business for years.  Companies like that care about profit margin, so they buy whatever is the cheapest that they can make the most mark up on, because even $0.01 per fastener, when selling 10,000,000 fasteners a year adds up to actual money. 

Companies like McMaster-Carr and Fastenal are hardware companies.  Both will tell you where the hardware comes from, and I have confidence buying from them, because their reputation and revenue are based on the success of hardware and little else. 

Summit and the Auto Parts stores are somewhere in the middle, but closer to the Home Depot model than the McMaster-Carr/Fastenall model.  Years ago NAPA only carried high end, USA made fasteners, but that's changed in recent years, again, because of the bottom line. 

In the end, none of these companies make their own hardware, so sure, there's some risk in all of them.  By that logic then one should only buy from a company that does, which both ARP and AMK do.  The argument that because a bolt has x number of marks in it means its truly a grade 5 or 8 regardless of where it came from to me no longer holds water.  If you are sure that they are using different material for both and not just stamping a different pattern into the heads of the same bolts and using a different coating then that's on you.  Understand that there's no recourse to these off shore companies if the part is bogus or fails.  International laws make it essentially impossible to go after them legally, and believe me, they know that.  Consequently I just don't trust anything made over there, and that's where most of that hardware comes from.  Maybe the companies that wholesale it to the stores you buy it from test it, maybe they don't.  Even if they do, do they test every batch?  The bottom line is that I don't risk my life or car on maybe. 

Honestly, if cost is such an issue, go to the local hardware dealer.  Around here its Lilly Fastener.  If I go in there looking for something oddball and they have it, which they usually do, they typically just give me what I need under the guise of "samples".  Its easier to just do that than fill out the paperwork for a handful of hardware.  I really try to do that only as a last resort, because I don't want to take advantage, or ruin a god thing.  I always offer to pay, but they just won't let me. 

Last edited by TKOPerformance (6/16/2018 10:57 AM)

Carroll Smith in his book "Engineer to Win" has a very informative chapter on fasteners. A must read imo.

TKOPerformance wrote:

  The argument that because a bolt has x number of marks in it means its truly a grade 5 or 8 regardless of where it came from to me no longer holds water. 

Good luck with that.

Luck is for the ill prepared, which ironically, is my entire point.