Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: Wangler on 31 March, 2024, 08:05:14 AM



Title: Flanged bolts
Post by: Wangler on 31 March, 2024, 08:05:14 AM
There seem to be many examples of where a 13mm nut or bolt with a washer could be replaced by flanged bolt.

Aside from purism/originality, is there any reason why one shouldn’t use a flanged bolt? I’m fed up with dropping washers!


Title: Re: Flanged bolts
Post by: chriswgawne on 31 March, 2024, 08:43:53 AM
Where one is screwing the bolt into aluminium (as is frequently the case with older Lancias), I would say that a floating washer was always preferable to avoid damaging the face of the aluminium. With a flanged bolt, the flange has to rotate as the bolt is torqued whereas with a floating washer, the washer can rotate against the bolt head, not the aluminium component the underside of the washer is sitting against..
Does that make any sense?
Chris


Title: Re: Flanged bolts
Post by: Wangler on 31 March, 2024, 11:21:51 AM
Thanks Chris

I understand where you’re coming from. My feeling is that they wouldn’t cause a problem, although I am happy to be disabused! I don’t see any problem with the exhaust manifold or engine mounts (obviously steel) or with certain bolt on bits such as the inlet manifold and carburettors. Anything with Allen bolts I would not change.

This is a very interesting website in respect of flange bolts.

https://www.fbabolt.com.au/flange-bolt-tech.html


Title: Re: Flanged bolts
Post by: Simon B on 31 March, 2024, 05:34:04 PM
Flanged nuts may have there uses but I would agree with Chris on retaining floating washers, certainly on aluminium. It likely wouldn't be your problem but trying to remove a rusty flanged nut from a steel assembly is also probably more difficult than a nut and separate washer.
Anyway who needs flanged nuts? Have you tried using your magnet to help fit stuff instead of just picking things up that have been dropped!
P.s. can I have your old fixings!