Safety wiring bolt heads, Do's and Don'ts...

[Road Trip]

Here's a little more info for anyone interested. The aviation general guidance for safety wire application is defined by the FAA in AC 43.13-1b. Lots of good reading and pictures starting on Page 328 of the PDF

https://www.faa.gov/documentlibrary/media/advisory_circular/ac_43.13-1b_w-chg1.pdf

After skimming through this document, I went ahead & downloaded it in order to
add to my personal library. Since it's only a ~20MB .pdf file, the storage cost on
today's Terabyte drives is miniscule.

Good stuff, Thanks!

 

[GoToGuy]

The 43. Series FAA circulars are are the THE word on various repairs and service, covers just about anything.
Wow that brought back memories the half moon type lock tab on early 60s, 70s , exhaust manifolds.
Sorry for the info overload on safety devices from antique, to warbird now heavy high bypass turbofan. A great amount is ISO, MS, AN, NAS industry standard and also Manufacturer specific replacement. The catalogs, manuals, Airworthiness Directives, Service Bulletins, PMA, let's just say it's challenging.

 

[HotWheelsBurban]

GoToGuy,

Your photo reminded me of some factory locking fasteners
I used to find on Chevrolet vehicles back in the day. More
specifically, needing to remember to bring a suitable flat
chisel to the Treasure Yard in order to be able to remove
the factory cast iron exhaust manifolds from a SBC...so
that we could take those double-bump heads with us. (!)
(see attached below -- replacements for sale at Jeg's.)

My curiosity piqued, I tried to find out a little more about
how Chevrolet essentially took inexpensive stamped steel
and allowed them to get the safety wire functionality for
1/100 of the installation time/labor/cost.

Once I tunneled down in some of the 100-point 'vette restoration
conversations, I found out that the actual name for these
things are "French Locks". (?)

Then I found a picture of a pair of fasteners secured by a factory
French Lock on the halfshaft of a '66 Corvette:

You must be registered for see images attach

(credit: corvetteforum.com (link)

NOTE: And if you find yourself riding around in one of these old 'Vettes as either driver or riding shotgun,
and you aren't absolutely sure that these are installed & providing the extra security against a halfshaft
loosening & flailing away (think of what little is between that halfshaft & your back) ...then run, don't walk
to these folks and buy a set asap:

Cheap insurance, yet often tossed/lost/forgotten by the PO. Don't leave the driveway without 'em!

You must be registered for see images attach

****

You know, this whole safety wire conversation has been really interesting.
Who knows? Maybe someone will read about our fixation with keeping
things together at high speeds & decide to add a little cheap mechanical
insurance policy here & there on their own project(s).

Positive locking for safety isn't only installing cotter pins on the steering
bits -- especially if you've added additional twist to your drivetrain!)

Safe travels --

I've seen these on the exhaust manifolds but didn't know what they were. Thanks for enlightening me!

 

[termite]

I've been thoroughly entertained with this thread and never thought it would bring out so many experts when I originally posted some crappy pics of a 100-year old tractor crankshaft, lol.

Makes at least two of us in that group, maybe more.

 

[Schurkey]

A downside to "French Locks".

If the metal is soft enough to bend without shattering, it's also so soft that the bolt-head will sink-into it over time. This reduces clamp load, leads to problems with the assembly.

I thought "French Locks" were essentially "illegal" on critical components--aerospace, nuclear, etc. And yet, I don't know why I think that, or where I'd have read it.

For the record, there are multiple books on fasteners and plumbing that's applicable to automotive use including but not limited to racing and custom vehicles. The absolute best of the bunch is Carroll Smith's masterpiece. EXTREMELY recommended. If you're on this web-site, you need this book.
www.amazon.com/gp/product/0879384069/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

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Also of interest are books by Mavrigian, Remus, John Deere, and Aird. They are not as good as Carroll Smith's in my opinion. Maybe others disagree. If you already have access to one of these (aside from the John Deere book) "upgrading" to the Carroll Smith book is strictly optional.

www.amazon.com/gp/product/1557885230/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

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www.amazon.com/Hot-Rod-Hardware-Timothy-Remus/dp/1929133014/ref=sr_1_1?crid=2ES583MTBZEEZ

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www.amazon.com/gp/product/0866913491/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

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[No link available for the Forbes Aird "High Performance Hardware". Apparently out-of-print. Was "HP BOOKS 1304", ISBN # 1-55788-304-1 ]

None of these are at the level of FAA or Military directives...which probably makes them an easier read, and more-suitable for our purposes. The John Deere book being the least useful, as it focuses on hardware used on tractors and agricultural equipment.

 

[GoToGuy]

Good suggestions Mr.Shurkey! All would be great starting points to begin the process of unbelievabley big the hardware world is. Walk in to local Ace, True Value, or other that's one type of hardware world. Everybody gets that idea.
But the other world , the specialized, specific, hardware world; the hardened , close tolerance , rolled threads, x-rayed, spline drive head, 175,000 psi. Comes in Titanium also but very expensive.
Want to learn hardware those books are some great choices.
Why is bolt stretch important? What is the plastic state of metal? What tragic event made the USA sit up and take notice of crap import hardware?
Good luck!

 

[Erik the Awful]

I got a $50 Barnes & Noble gift certificate for my birthday and tried to find Carroll Smith's hardware book on their website. They don't have it. I ordered David Vizard's book on cylinder head porting instead.