Washer types - when, where, how & why?

[myredracer]

Just bolting on the ancilleries and misc. bits and pieces to an old engine & ****** that have been rebuilt. It's been a long time since I disassembled it all. It just occurred to me I don't know what type of washers to use and where. Same question will apply to putting everything else on the car back together.

There's split lock washers (thin & thick styles), internal & external tooth lock washers, spring washers, standard flat washers, thin & thick flat washers, etc. and also nylock nuts. Bolts can be coarse thread or fine thread with different holding power. Sometimes you need just a flat washer and sometimes no washer. Sometimes you need a flat washer plus a locking washer. Does a flat washer go on first, then the lock washer? What about when to use loctite? What about high heat locations like exhaust? Is grade a concern? Is it poor practice to reuse lock washers? Should washers always be plated or are unplated okay in some cases? Does it make a difference if the pieces you are fastening together are both steel or aluminum or one of each?

Is there a website somewhere that will explain this or are there some general rules of thumb?

Thanks!

 

[finn]

Split lock washers are rarely used in quality designs, as they are ineffective.

The star type washers are sometimes used for electrical grounding purposes.

Plating is mostly for appearance purposes, ie storage and shelf life, although phosphate coatings, rather than cad platings, are common in the automotive and industrial world.

Bolts work by stretching, and thus creating a clamp load. A washer is used to provide bearing area to distribute the load without galling the base material.

You will never see a split washer on a high performance joint.

 

[Colin Len]

Not sure exactly what sort of vehicle you're working on but the first, obvious, thought would be to just use what it came with from the factory and not bother over thinking it. If you don't have the OEM hardware can you order it or at least research what size/type of hardware was used? I'd let the engineers who designed the vehicle do all of that figuring out instead of me worrying about it.

 

[L5wolvesf]

Here is one and there is a site that explains in more detail but my bookmark is **** (must have rattled loose).

https://www.fastenal.com/content/documents/FastenalTechnicalReferenceGuide.pdf

 

[L5wolvesf]

Found it

http://www.boltscience.com/index.htm?

 

[ZipSnafu]

Here is one and there is a site that explains in more detail but my bookmark is **** (must have rattled loose).

https://www.fastenal.com/content/documents/FastenalTechnicalReferenceGuide.pdf

That is a very handy guide you linked there.... thank you

 

[myredracer]

Not sure exactly what sort of vehicle you're working on but the first, obvious, thought would be to just use what it came with from the factory and not bother over thinking it.

1960s Fiat Abarth race car project. Some things I've done aren't original and some are aftermarket or original performance parts and mods. I have boxes of assorted rusty & greasy nuts, bolts and washers from at least 1/2 dozen Fiats over the years. What goes where made sense when I took everything apart a couple of decades ago...

Nowadays I put a nut and washers back on a bolt before storing it, put a note in the baggie or make a sketch with notes or sometimes take a pic.

I've kinda wondered about the effectiveness of split lock washers.

 

[L5wolvesf]

That is a very handy guide you linked there.... thank you

You're welcome.

 

[L5wolvesf]

1960s Fiat Abarth race car project. Some things I've done aren't original and some are aftermarket or original performance parts and mods. I have boxes of assorted rusty & greasy nuts, bolts and washers from at least 1/2 dozen Fiats over the years. What goes where made sense when I took everything apart a couple of decades ago...

Nowadays I put a nut and washers back on a bolt before storing it, put a note in the baggie or make a sketch with notes or sometimes take a pic.

I've kinda wondered about the effectiveness of split lock washers.

We are brethren, one of my race cars is a Fiat, perhaps we should talk. Never thought I would come across another Fiat racer here. PM me if you like.