Technical Nuts and Bolts

I know we’ve talked about nuts and bolts before, and with the changing times we are living through, I started wondering where everyone was purchasing quality fasteners from. That one in the picture is one of three that held the engine stanchion on the wings of the DC10s, which as you may recall, lost engines on occasion. The worst accident took the lives of everyone on board. I had a contract with the aerospace fastener industry to perform certification tests for a new generation of fasteners, in particular the materials used to manufacture them, after that accident. The FAA requires a series of tests before they will approve the use of the new fasteners, and there is a series of testing that is performed in groups of 3. Ultimate tensile strength, fatigue resistance, stress corrosion cracking, and 4 other tests, which I cannot remember. The company sent me 24 of these bolts to test, and at the time, approximately 1987? they cost just under $400/each!

That bolt above has been on every one of my desks at the labs I worked at since, and has never corroded from being handled. I have never oiled it, or even purposely wiped it off. It still looks new. I would love to use that quality of fasteners to assemble the whatever project, but I think I would go broke buying them. So now I’m looking for information about reputable brands and sources of quality bolts. The first one that came to mind is ARP, and they have lines of non-engine specific fasteners, however they are expensive.

So, bottom line, besides risking hardware store fasteners are actually grade 5 or grade 8, where do you all get your fasteners from?

 

The best ones come from old cars.

 

McMaster Carr has good stuff

 

I use McMaster, too!

 

One thing and I'm sure you're well aware of is aircraft hardware specifically bolts and nuts are chosen for specific stresses and applied accordingly. So while it might be strong as hell applying it to a automobile application may lead to catastrophic situations including death.

So what I'm saying is being an Aircraft Fastener doesn't mean it will work anywhere. The other caveat is the same principles apply to ANY fasteners used in Automotive applications...

I am a former MDC employee so yes that's a beautiful Bolt and it looks like Titanium...

I recall using a Titanium bolt in my mechanical brake clevis on my rear brake rod of my 1957 Hydra Glide and in a period of a year or so it wore half way through the bolt. So I was surprised but obviously not aware this type of moving contact was not a strength of titanium.

 

ARP if it's on my car's engines.
ACE Hardware if I need chrome or stainless stuff.
Forth drawer down in my toolbox it is on someone else's car

 

Fastenal is a place that seems to understand fastener properties...

...and another small but very popular one

Local to Perth, On, Canada

Valley Tool & Fastener

https://share.google/nF2QSzvWscfnuTrzz

Again I can't stress enough to know what your dealing with or ask and remember not all people selling this stuff understand its application properties.

 

Lawson products are good.
Dan

 

Several quality suppliers have been mentioned. I like the McMaster-Carr online site as you can see a complete spec sheet and a CAD drawing for any nut or bolt.

 

Bolt Depot.Hingham Ma.

 

Dave, I've never used them but have you heard of Supertanium fasteners, at one time they were top shelf racing hardware, these guys have come up in past searches.
They aren't cheap though.
https://www.lawsonproducts.com/collections/bolts-wf40

 

@Dave G in Gansevoort, that bolt was used in an application were all members involved did not move...the stresses were there but nothing that would wear or stress the bolt to failure under approved flight and maintenance procedures.

The accidents you mention were caused by improper maintenance operations by the Company that purchased the Aircraft. They literally used a forklift to wrestle the engine off or on fatiguing the structures. Not the right method at all.

Unfortunately the big finger gets wagged towards the manufacturer in the process. Didn't mean the culprits didn't pay for it as well...but it was ugly...we made those wings too... That aside Manufacturer's are also not immune to failure either. In the case above they were immune although affected.

We feel the pain no matter the cause...

 

I keep a decent inventory of bolts that came off motors that I had for parts. I also have quite a few body bolts too. I've never had any problems with used bolts. I always make sure they are clean and rust free. I have also used McMaster-Carr, when necessary, they seem to have good stuff.

 

I got the head bolts for my flathead from Caterpillar. Used their bolts all over the engine in other places as well.

 

I miss Boeing surplus

 

We had some surplus sales at MDC and Boeing but nothing like the stores your way...I still have some great items that will outlast me...

 

I have sat in on a couple two hour seminars on Caterpillar fasteners with one of their engineers, one wouldn’t think there’s any way to make four hours on bolts interesting…it was.

 

This Thread makes me think of Hamber @AULIZ in a good way of course. I'd be interested in his avenues. I know he is big on @squirrel's advice but also sources new as well...lots to know.

I remember an 88 year old Farmer I rented a Trailer Home for a couple years from. He had a workshop that he let me use. His surplus fastener collection was eye opening...that was a way of life for the older crowd...and no surprise Hotrod/Custom/Race as well...there were way more have nots than than have's...can you imagine the stats for bad outcomes over the years......hopefully not so bad and we must also remember new stuff fails too...

My bolt wearing through was a reminder that could have been otherwise...

Oh yeah then there's torque...

 

I prefer to get from a hardware-centric retailer when it's a serious part.
We have a Fastenal locally.
Used to have a Copper State, too, but they closed and the nearest is in Flagstaff.
For less critical, I'll go to the local hardware store. Both in this small town have open bins and bags you write on. If it was just blister packets like the auto parts stores here, I'd shop online.
I've used Gardner-Wescott decades ago with good results, and ARP.
Mcmaster has been used more recently, and I really like their online catalog to look things up.

 

McMaster Carr had nice catalogs...remember those...as did Fastenal...

 

No, it’s a cobalt alloy, and extremely tough, while also having a very high ultimate strength of 190,000 psi. It had approximately 15% elongation at yield. That bolt was 1.5 inch diameter, so when one finally broke in our 1 million pound load frame, it sounded like a cannon firing!

Don’t know what happened. I think this is a repeat from earlier.

 

Yes, I know. We had those new bolts long before the results of the accident investigation were released. And what prompted me to start this thread was I saw a show on Science channel or National Geographic that was about that exact failure. Battelle people were involved in that investigation, and probably were helping with the fatigue investigation, as they had one of the most powerful SEMs in the country to evaluate the fracture surface.

That show was a bit misleading, inferring that the cause was determined within weeks of the accident. I believe it was more like a year or more.

So back on topic, yes I’ve used Supertaneum fasteners, but thought they had gone out of business. My friend Jim had one of their selection setups, that the regional rep would stop by and refill on a routine basis. Jim was a fabricator and built race car chassis along with the other work he took on to stay in business when the car side was slow. So it’s good to know they are still available. We have a Fastenal locally, and I’ve bought some fasteners from them, just didn’t know what the quality is.

Like also mentioned, I also use ARP for engine stuff, as it is easy to get anything for small block Chevy engines. They are prepackaged from the oil pan to the carburetor, and everything in between. And my ot Austin A-series engines is bolted together with their fasteners.

Good information, thanks…

 

McMaster for the good stuff, Bolt depot for cosmetic (trim) stuff

 

It was @DDDenny that mentioned Supertanium but I guess your referencing the alloy...which I'm sure each fastener has a mix as all are based on testing results you employed...yeah sounds fricken dangerous. Failures can definitely be violent.

 

Lawson True torque are as good as you will find outside of specialty bolts like the one you have there or ARP specialty bolts.
Back in the 70's I got my grade 8 bolts from Cat equipment because they were a bit hard to find otherwise at the time.
Still you have to fit the strength and quality of the bolt to where you are using it. Simply meaning that you don't need grade 8 bolts to hold fenders on where a grade 2 bolt works fine.

 

Unless something changed recently our local Fastenal doesn’t allow walk in purchases anymore. A few years back I was looking for a metric bolt for an OT motorcycle engine mount. Fastenal didn’t have one and couldn’t get one. I got one at the local ACE hardware store. Fastenals HQ is an hour away in Winona MN and I wasn’t impressed with their store in Winona either.
Dan

 

I have to agree with this, I've tore down several Model A's that were field cars and seldom broke a bolt spray a little penetrating oil on them and they come loose. I try to use grade 5 or 8 bolts rather than the cheap junk from the local hardware store, I've had the cheap bolts shear off on the shock mounts on my V8 A where they were bolted to the frame.

 

I experienced that years ago with them. I'm not sure they are all account based. Sometimes you have to open an account though...as long as they don't have limits to qualify...McMaster Carr may have had a similar policy...I never went to a store for them...

 

In my area Blaine’s Farm & Fleet has an extensive selection of fasteners, from not marked to Grade 5 and Grade 8, metric and stainless too. Some of the Ace Hardware stores have large selections like that also. I’m not a metallurgical engineer nor do I have a Tinius Olsen tensile testing machine but I use a rudimentary way to check for Grade 8. If a file just glances off a bolt I consider it just case hardened, but when cutting with a hacksaw and it feels gummy I believe it’s G-8. Or is this just foolishness?

 

Another thing that I like to do is if a bolt is in shear, either single or double, is to make sure that the part of the bolt in shear is not threaded. That means I frequently have to add a spacer and a little longer bolt, which means I have to shorten the threaded end, which is a time consuming pita. However I can then feel confident that the shear load will not exceed the shear strength of the bolt. I was trained to use 1/2 the ultimate strength for shear strength. So making sure that the shank is in shear and not the threaded portion, I can determine what the maximum load can be. Then I still add a cover my ass factor. Just because…

Double shear is best, but if it can’t be done, try to make the fit as snug as practical. There will still be bending loads as well as shear loads with single shear, but this will make a bit of a difference.

Now this will make everyone say what the…

When I first started helping out on other people’s race cars, an old timer said to me that there were a few places on a car that he just didn’t use high grade bolts for. An example, front suspension, 4-bar on tube axles. The way that cars were built, the frame end of the 4-bars were in single shear. Everyone back then built for strength, so the spherical rod ends typically were either 5/8th or 3/4 inch rod ends. Sometimes the front at the axle, where you could use two plates to attach the rod ends to the axle, would be 5/8th rod ends, and the back end would be 3/4 rod ends, but in single shear. His point was that a low grade bolt would bend during the normal racing is rubbing stuff, so that meant that the wheels stayed on the car. Maybe not quite straight, but still running.

I must say, as the trend was going to smaller rod ends, that concept was not followed. A 3/8th rod end in double shear, I’m going with better bolts!