Rocker assembly

[David Withers]

Re: \"thou\" and \"mil\", my experience is exactly as Alec\'s but maybe there\'s a difference between mechanical and electrical/electronic engineering \'speak\'.  A rather dangerous difference though!
One thing I like about the railway preservation scene is that it\'s almost all imperial.  Hard to envisage a 34.925 mm Whitworth bolt in place of a 1.3/8\"!
There are some oddities though.&nbsp; The bolts and nuts on the Danish loco that I\'m working on&nbsp;are hybrids&nbsp;having Whitworth threads&nbsp;but Unified Heavy Series hexagons.&nbsp; Note: For any other sad anoraks like me, that\'s BS&nbsp;84 threads and&nbsp;BS 1769 heads!&nbsp; <IMG>&nbsp;&nbsp;<IMG>&nbsp;
It\'s not only steam locos that have&nbsp;funny fasteners.&nbsp; Some Fords of the 1960s/70s had a mix of imperial, metric and imp/metric hybrids - all on the same car!&nbsp; Thankfully our Triumphs have&nbsp;only Unified Normal Series (BS 1768!) -&nbsp;so far as I know.
Tune in next week for another episode&nbsp;of this&nbsp;captivating drama!<edited><editID>Dizzy</editID><editDate>39372.8389467593</editDate></edited>

[rey808k]

i agree alec,<br><br>i worked for a diamond tool manufacturer and i used to work to \'thou\'s, 0.001\" <br>it was not refered to as \'mil\' for me<br>

[Alec]

Hello Dizzy, <br><br>reference threads and heads,&nbsp; Morris bought a French engine manufacturer but when he used the engines in his cars he retained the metric threads but used Whitworth hexagons!<br><br>REY808k, not in Colwyn Bay by any chance? (Noting the Welsh registration number, I once had a Wolseley 1500, DEY 888 which was once owned by the Anglesey MP, Cledwyn Hughes)<br>

[Mike Stevens]

Hi All,
Maybe it\'s me then.&nbsp; Certainly to me, \"thou\" is 0.001\" and so is \"mil\".&nbsp; I guess \'cos we have some American ancestry here at work maybe that\'s where it comes from.&nbsp; It\'s when they say \"3.5 mil\", is when I say \"do you mean 3.5mm or 3.5 thou\".&nbsp; It\'s always the former.&nbsp; The dictionary lists \'mil\' as 1/1000 inch...
As well as the Triumphs, My everyday car is a Jaguar (sorry!) which is in the main Metric and I also have an early series I LandRover which is \"Whitworth\", by which I suppose&nbsp;I really mean BSF?&nbsp; Over the years I have certainly accumulated a number of spanners which are labelled x/xW, (for example).&nbsp; I am also lucky to have acquired a complete set of Warrior BSF taps and dies.&nbsp; Lucky chap...
Time to move on....!
Cheers, Mike

[Clifford Pope]

What I like is working on a car that has had all its nuts and bolts randomly replaced out of someone\'s odds and ends box, so has a mixture of threads and flat sizes. There\'s nothing quite like lying under the car trying to match up bell housing bolts, alternately trying to reach for one of half a dozen similar but different spanners. Or finding with the nut half on that the thread isn\'t quite the same.

[David Withers]

A Google search brings up lots of references of \"mil\" as .001\".&nbsp; Seems it\'s an abbreviation of milliinch!&nbsp; How absurd, applying a metric term to an imperial measurement!
It does seem mostly American but it appears some misguided Brits use it as well, e.g. see <A>http://www.bbc.co.uk/dna/h2g2/A471476</A>
I\'ve been&nbsp;working with \'thous\' almost daily since 1959 or&nbsp;earlier.&nbsp; Never before&nbsp;heard them referred to as \"mil\".&nbsp; It\'s about as desirable as that other \"mil\", my mother-in-law!
Good description of mixed threads and&nbsp;hexagons, Cliff.&nbsp; I expect we\'ve all come across this at some time.&nbsp; The very worst examples are UNC&nbsp;fasteners screwed into Whitworth tappings, made possible because all sizes other than 1/2\" have the same TPI!&nbsp; The different thread angle (Whit 55 degrees and UNC 60 degrees) means that the threads are engaging crest-to-root instead of flank-to-flank,&nbsp;a sure recipe for loosening in service!&nbsp; Doesn\'t affect cars much as they rarely used Whit (they used BSF which has a different TPI to UNF), but&nbsp;it\'s something to be watched for&nbsp;on steam railway locomotives.

[David Withers]

Mike, you mentioned that your Land Rover has Whitworth, \"by which I suppose&nbsp;I really mean BSF?\" you say.&nbsp; Both have threads of Whitworth form so, yes, they are Whitworth whether BSW or BSF!
No need to be&nbsp;embarrassed about having a Jaguar.&nbsp; As my signature shows, I have a Rover 75 with a BMW engine and I\'m happy for anyone to know!
Last I heard, both Jaguar and Land Rover looked set to become part of the Indian firm of Tata.&nbsp; MG-Rover has gone down the spout of course, but better to die gracefully than sell out to a phut-phut wheelie-bin maker! &nbsp;<IMG><edited><editID>Dizzy</editID><editDate>39373.7536226852</editDate></edited>