Toyota bolt corrosion resistance

[doru]

Hi all,

I own a '97 Camry and the '13 LX.
I noticed that Toyota bolts even exposed to the elements for years are still in good condition.
When I use aftermarket fasteners even zinc plated and all that they do not last.
What makes the Toyota bolts so good, besides the $$?
If you can get it as technical as possible / go into the weeds with it, it will be great.

Thanks

 

[OSS]

Toyota bolts aren’t zinc plated. They used to be cadmium plated but I don’t know what they’re using now.

 

[clx16]

Found some fasteners on scions look to be stainless steel. When I go to the self service salvage yards, I harvest nuts and bolts from all the Japanese vehicles. You do not want to harvest from US or German vehicles as those seem to both rust and you also introduce odd sizes like 11mm, 13mm, 15mm and 16mm sizes.

 

[doru]

When I go to the self service salvage yards, I harvest nuts and bolts from all the Japanese vehicles. You do not want to harvest from US or German vehicles

So what's the Japanese secret sauce?

 

[linuxgod]

I don't know what Toyota uses but there are lots of different Zinc coating options

Corrosion Resistance of Zinc Plating - Sharretts Plating Company

UPDATE (4/16/2021): SPC is no longer taking on new business for zinc plating. Please refer to our coatings page to learn about the other coatings we offer. If you’re contemplating the best way to protect metal surfaces against the relentless forces of corrosion, a simple phrase to keep in mind...

www.sharrettsplating.com

Most likely it's some sort of zinc alloy. I'm not a chemist or metallurgist but apparently combining two decent corrosion-resistant metals like zinc and nickel result in an alloy which is much more resistant than either of the individual coatings.

Zinc vs Zinc Alloys - Sharretts Plating Company

Zinc is a hard, brittle metal that is found in abundance in many parts of the world. Zinc electroplating offers an inexpensive alternative to precious metals such as gold, silver and platinum. Its relatively low cost makes the zinc plating process the top choice for companies looking for...

www.sharrettsplating.com

Or they may be using something aside from Zinc

Understanding Fastener Platings and Finishes - Fastener Mart

To prevent corrosion, or to improve appearance, many fasteners are plated. This article describes common platings that are used for different applications.

www.fastenermart.com

Toyota bolts do rust though they do hold up pretty well considering

 

[Zjohnsonua]

They use all kinds of coatings. And coatings over coatings at times. Cadmium comes in a few different valence-levels that offer varying amounts of high level corrosion resistance at the cost of manufacturing toxicity. Zinc comes in with lower toxicity, but lower corrosion resistance, so other coatings get applied to toughen it up. There are combinations of other treatments that leave you with the dark olive drab color you see on the interior fasteners.

We have a guy whose full time job is clearing fasteners for use in specific environments...it isn't trivial. As much as I like wading into the weeds, this is one where even with the access, I haven't delved very deeply.

 

[fjc-man]

If the bolt / fastener doesn’t require loctite or sealant, I apply this stuff to the threads. Always comes apart with no problem after that. Made by a company called Sanchem,inc

 

[clx16]

Generally the fasteners that seem to last the longest are the "gold" colored zinc coating with actual paint on them. I usually go after the ones that have been painted along with the body parts from the top of the fenders and firewall. The interior ones lack the painting and are fine but I try to keep those as interior use.

 

[MoJ]

The surface prep method is as important as the final coating