[ROVERNET - UK] P6B nuts and bolts specs

Warwick Brooks warwick at regscom.com.au
Tue Nov 6 01:36:35 GMT 2007


Just thought I would add this bit of info that may not be apparent to all,
regarding BSW (Whitworth) and SAE (AF).  That being that SAE is the standard
(Society of Automotive Engineers) while AF simply means Across the Flats and
refers to the size of the bolt-head when measured from one side of the
hexagonal head to the other, across the flats.

Therefore a 1/2" SAE bolt-head is 1/2" across and the corresponding spanner
is 1/2" plus clearance between the jaws.  Metric sizes are also measured
across the flats so a 12mm spanner fits a 12mm head.

Whitworth or British Standard Whitworth sizes are based on the shank size of
the bolt, not the head.  So a 1/2" BSW bolt fits a 1/2" hole (plus
clearance) and so the head is much bigger across the flats.

This is why an SAE 1" spanner is marked 1" AF and is a reasonably large
spanner, while a 1" Whitworth spanner is marked 1" BSW and is a bloody big
spanner.

Now having just gone to the trouble of writing this it occurred to me that
somewhere on the web, someone may have done a better job of it, so I looked,
and they had, and it was.

So here it is...

http://www.internationalcockpitclub.org.uk/articles/article_threads.htm

Regards,
Warwick. 

-----Original Message-----
From: rovernet-bounces at lyris.ccdata.com
[mailto:rovernet-bounces at lyris.ccdata.com] On Behalf Of Brooks
Sent: Monday, 5 November 2007 11:33 AM
To: rovernet at lyris.ccdata.com
Subject: Re: [ROVERNET - UK] P6B nuts and bolts specs

 Thank you ...that was extremely informative and appreciated.

Regards

 Dennis


----- Original Message ----- 
From: "Aidrian Bridgeman-Sutton" <smokeandsteam at gmail.com>
To: <rovernet at lyris.ccdata.com>
Sent: Sunday, November 04, 2007 8:12 PM
Subject: Re: [ROVERNET - UK] P6B nuts and bolts specs


> On 11/3/07, Brooks <restore at nbnet.nb.ca> wrote:
>> "the car is UNF and UNC
>> throughout."
>>
>>  I'm sorry...but I don't know what these terms represent...
>
> "Unified National Fine" and "Unified National Coarse" which were
> originally specified in the 19th century and eventually became US
> standards. You will also see them referred to as SAE threads. Your
> standard toolkit will fit
>
> SAE/Unified threads began to  become more widespread among British
> makers in the 50s into the 70s until metrication; the "Unified" part
> of the name comes from an agreement among various standards bodies in
> the late forties to ensure at lest some commonality between the
> various inch-based countries in NATO.
>
> Carbs, electrical parts and instruments were often held together with
> BA (British Association) screws; BA is a long established thread form
> used in instrumentation and is based on a metric measurements, but is
> not compatible with the ISO metric system except by accident.
>
> While technically obsolete  BA hardware and tools are still available
> as BA screws are much favoured by model railway enthusiasts in the
> Commonwealth countries
>
> Having said that there is one other thread standard you need to be
> aware of, BSP which is sonetimes used for things like temperatore
> sensors and which can trip up the unwary.
>
> Aidrian
>
> _______________________________________________
> rovernet mailing list
> rovernet at lyris.ccdata.com
> To unsubscribe, go to this web page, look near the bottom and follow 
> instructions:
> http://mailman.nipltd.com/mailman/listinfo/rovernet
> Back-up list and photos at:
> http://autos.groups.yahoo.com/group/Rover_net/
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database: 269.15.21/1109 - Release Date: 
> 04/11/2007 11:05 AM
>
> 


_______________________________________________
rovernet mailing list
rovernet at lyris.ccdata.com
To unsubscribe, go to this web page, look near the bottom and follow
instructions:
http://mailman.nipltd.com/mailman/listinfo/rovernet
Back-up list and photos at:
http://autos.groups.yahoo.com/group/Rover_net/




More information about the rovernet mailing list