Bolt sizes..................Question
7 posts
• Page 1 of 1
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
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
-
berni29 - Third Gear
- Posts: 387
- Joined: 10 Mar 2004
- Location: Beckenham Kent
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
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
-
steveww - Coveted Fifth Gear
- Posts: 1838
- Joined: 18 Sep 2003
- Location: Northamptonshire, England
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.

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.
-
M100 - Fourth Gear
- Posts: 766
- Joined: 16 Sep 2003
- Location: Yorkshire
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
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
John
No longer active on here, I value my privacy.
No longer active on here, I value my privacy.
-
nebogipfel - Coveted Fifth Gear
- Posts: 1588
- Joined: 25 Sep 2003
- Location: Norfolk UK
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!
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!
-
berni29 - Third Gear
- Posts: 387
- Joined: 10 Mar 2004
- Location: Beckenham Kent
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
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
- carrierdave
- Third Gear
- Posts: 333
- Joined: 23 Sep 2004
- Location: Rochester, Kent
You can get High tensile SS bolts. See http://www.southcoaststainless.com/Page40.pdf But they are not cheap!!
Mike Geiger
66 S3 Coupe', no more
66 S3 Coupe', no more

-
type36lotus - Fourth Gear
- Posts: 577
- Joined: 17 Sep 2003
- Location: Tampa, Florida, USA
7 posts
• Page 1 of 1
Total Online:
Users browsing this forum: bdea and 8 guests