Bolt strength + material

Does anyone know what strength bolts are needed for front beam and other suspension parts on a beetle? I have some which are 10.9 that I wanted to use. Also can these be stainless or not a good idea?

Also what is the go with using stainless bolts on mild steel threads e.g. wings, body bolts etc? Heard that it is not a good idea to mix - is this true?

Stainless on non structural areas is fine. Make sure you use anti seize to stop galling. Would not use on suspension parts due to impact fatigue. Check the head of your original bolt it should have the number or star marks setting material strength.

most bolts for suspension should be grade 8 as they are strong and yet still abit flexable. stainless is supposed to be inert however can still be a bit reactive if they arent the best quality. but all information contained in this ramble is not to be used as a replacement for qualified engineers advice!

The same engineers that built The Shuttle (-2),That Wobbly bridge,The Titanic, The P76 and The Hindenburg......Oh the humanity. 👍👍

if you are using stainless make sure it is 316 grade not 304. the 316 is a marine grade so will hold up much better than the generic 304 grade.

Also most SS bolts are not high tensile grade so best to use these on only non strutural stuff, gaurds and such are okay but definitely not for suspension and safety type applications.

metric high tensile bolts start at grade 8.8 and as Mactaylor says they have the grade stamped on the bolt head.

Aussie wrote:Does anyone know what strength bolts are needed for front beam and other suspension parts on a beetle? I have some which are 10.9 that I wanted to use. Also can these be stainless or not a good idea?

Also what is the go with using stainless bolts on mild steel threads e.g. wings, body bolts etc? Heard that it is not a good idea to mix - is this true?

Hi
You shouldn't use stainless steel bolts on the front or Rear suspension as they aren't High Tensile enough...
Best to use 10.9 grade ...

stainless steel bolts can be used on the body etc..
Guards - Running boards etc..

with anti seize or lithium based moly grease on the threads...

not sure what You mean "not mix" You can use basically any bolts on the guards , steel - stainless - titanium - zinc coated etc...

or a mixture of these.. ... IMHO..

Lee

I used zinc plated Hi Tensile bolts with zinc plated washers and anti seize ... they have since been painted with killrust paint.. so they shouldn't rust... Lee

These are the bolts I was planning to use. Does anyone know by the markings whether they are stainless or not???

Sounds like the other non structural ones in stainless will be OK with some copper grease anti sieze.

With regards to mixing materials I am assuming you mean things like stainless bolts and regular steel panels. In which case using stainless is a bad idea. This question has been asked many times on this forum. This article sums it all up for you, http://www.azom.com/article.aspx?ArticleID=98.

It's like that experiment you do as a kid, putting a steel and copper nail into a lemon to create a battery. Same principal applies here. Using materials as similar as possible is best, hence steel panels and gal (zinc plated) bolts.

In that articles you will see steel and zinc are very closely located in that table, which is a good thing.

Steel and stainless on the other hand are far apart and that is a bad thing.

I for one will be using galvanized bolts when the time comes.

Aussie wrote:These are the bolts I was planning to use. Does anyone know by the markings whether they are stainless or not???

Sounds like the other non structural ones in stainless will be OK with some copper grease anti sieze.

Hi

they look like zinc coated steel HI TENSILE bolts...

which is great...

many people use stainless steel bolts to hold the guards on
as they do not rust... and if coated with antiseize they shouldn't cause any problems...

still a lot better than plain steel Hi tensile bolts which can rust in the thread,...

most stainless steel bolts are smooth and shiny silver
not quite bright as chrome...

Galvanised bolts are usually NOT high tensile .... and the surface is rough ... and can be dull silver..
never bright and shiny like zinc plated...

in the USA and UK You can buy stainless steel bolt and washer kits to bolt on the 4 guards/fenders/wings..
they wouldn't use anything else... lol

IMHO

Lee

Some useful links:

http://www.totallystainless.com/yoursafety.htm

http://www.totallystainless.com/totallystainless.htm

hth