Where do I get rust proof dome headed screws?

[OM2]

I needed for my double glazing windows.
Existing screws have rusted.
I bought some maybe 2 years ago from ebay.
These have rusted as well now.
Can someone tell me where to buy from?
Want to buy a pack of 100 say.
Don't want to go to b&Q and pay £1 per screw.
Online purchase would be preferred... but what do I need to look out for?
Like stainless steel or have some sort of coating?

Thanks.

 

[SFK]

OM
You did not give screw dimensions, but...

"A3 Stainless steel" is the best for anti corrosion
"A4 Stainless steel" is better if near sea due to its increased resistance to chloride corrosion.
Note that they will still corrode, but not rust.

So suggest a search for "dome headed screws A4 stainless"

https://www.ebay.co.uk/sch/i.html?_...itleDesc=0&_osacat=0&_odkw=dome+headed+screws


--------------
The two most commonly produced grades of stainless steel are 304 (known as 'A2') and 316 (known as 'A4'). Both of these grades will offer excellent corrosion resistance, cleanability, and the ability to handle extremely low (cryogenic) and high temperatures.

Grade 316 ('A4') is also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304.

The basic chemical compositions of these two grades are as below:
Grade 304 stainless steel (A2): chromium 18% + nickel 8% (known as '18/8')
Grade 316 stainless steel (A4): chromium 18% + nickel 8% + molybdenum 3% (known as '18/8/3')
------------

 

[EddieM]

Use a lot of A4 (316) here, coastal area corrodes "normal" steel at pace.

 

[JohnD]

btw a lot of Chinese stainless steel is very poor quality because they often make it without using nickel.

You can make an 18/0 stainless just alloyed with Chomium, but it is hardly fit for a cafe teaspoon.

Nickel increases strength and corrosion resistance greatly.

however it adds to cost. I can't see price charts but it hit around $18,000 per ton last year. Recently around $14,000.

Miners say that once China starts producing more good-quality steel, nickel mine owners' sales and profits will increase.

 

[EddieM]

Yes, one has to be wary of where one gets stainless steel products from. EBay is a bit of a lottery. You really want US or EU stainless.

 

[dontbelieveawordofit]

general rule , if you can pick it up with a magnet it’s poor quality.

 

[SFK]

Eddie and John, Definitely correct on that - although I provided the link I too am distrustful on buying SS from eBay (or others) as getting certification is near impossible for small batches.

Limit of my testing ability is buying SS and testing with strong Magnet to ensure it is not Steel (SS is typically non magnetic).
But this is not a good test for quality.

For larger qualities would go to sites like this (not used this company - only for reference but search shows that they know differences between A3 and A4 and are supplying to marine).
https://www.westfieldfasteners.co.uk/Ref_Grades_of_Stainless_Steel.html
SFK

 

[OM2]

Thanks for the replies guys
I'm sure I must have asked here a long time ago where to get dome screws.

ebay: I want to avoid.
westfieldfasteners - assuming they expect orders of 1000's?
Don't screwfix or toolstation have?
Where do builders go to buy?

Dome screws for windows... is it OK to use socket heads?
I'm guessing no for some reason? I've never seen on any of my windows - the ones there are always dome with a lip.

Thanks.

 

[EddieM]

Thanks for the replies guys
I'm sure I must have asked here a long time ago where to get dome screws.

ebay: I want to avoid.
westfieldfasteners - assuming they expect orders of 1000's?
Don't screwfix or toolstation have?
Where do builders go to buy?

Dome screws for windows... is it OK to use socket heads?
I'm guessing no for some reason? I've never seen on any of my windows - the ones there are always dome with a lip.

Thanks.

If you search for Chandlery supplies, you can get a large range of marine (DIN certified) stainless fixings and fasteners.