Bolt sizes..................Question

[berni29]

Hi Guys

I have just stripped my plus 2 engine bay, and most of the very rusty bolts were 7/16th headed and about and inch long. I want to order replacements in stainless steel, but what is the correct description of them? I have some M6 which fit but feel slightly loose. Are there any other common sizes that I should order?

Many thanks

[steveww]

All the bolts are imperial so do not try to force fit any metric stuff in there. The threads are either UNF or UNC.

Warning about stainless steel, these are not as strong as the passivated steel originally used. Only use stainless where strength is not important. New passivated steel bolts will last for years especially if you are only using the car in sunny weather.

A good source for all your bolts etc is www.namrick.co.uk

[M100]

Definitely a big no to stainless for anything that is stressed. It might look nice and shiny but you might find the last person who is commenting on this is the accident investigator

Look in the parts list, all (well nearly all) the fasteners are explicitly coded in their part number as to the type/diameter/length/thread etc. The decode table is at the start of the parts book.

[nebogipfel]

Agreed use stainless on the pretty stuff by all means but HT mild steel on all the mission critical stuff.

I had a friend who used stainless on a classic bike resto' and was horrified when they fatigue failed!

All hexagons should be good old AF and threads UNF and UNC (coarse threads mainly into threaded aluminium and cast iron.

John

[berni29]

Hi

Did not realise that about them being weaker. Will use plain old HT. I used stainless for the sill bolts....arre they highly stressed? I guess not.........

Many thanks!

[carrierdave]

Hi Berni,
All the high tensile bolts should hace 3 small lines/upstands on the top of the bolt head - this designates that they are high tensile steel.

rgs

David

[type36lotus]

You can get High tensile SS bolts. See http://www.southcoaststainless.com/Page40.pdf But they are not cheap!!