SEM article

Evenin' all,

reading the Amanco restoration article in SEM tonight, I was struck by two points which puzzled me. I freely admit to knowing little about Amancos apart from recognising the common ones, and admiring the bigger models.

The writer made great play of using the correct Whitworth taps and making replacement nuts to the correct Whitworth sizes. Did Associated Manufacturers use Whitworth fasteners in the 1914-16 period?

Later he mentions that Amanco cranks are very solid castings. Surely they were forgings?

Comments would be welcome.

Regards, Arthur G

Reply to
Arthur G
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It looks like a forging to me. I know not whether AM used them but if you drag out an old Machinery's you'll find all sorts of odd threads including Whit. Needless to say American Whit is slightly different to BSW :-) I see that Alistair Campbell is now writing the Anson's press releases :-) regards Roland

points which puzzled me. I freely admit to

admiring the bigger models.

replacement nuts to the correct Whitworth

were forgings?

Reply to
Roland Craven

Perhaps the restorer found some 1/2" 12 TPI fasteners and assumed Whitworth, when in fact the Yanks used 1/2" 12 TPI before changing to 1/2" 13 TPI? Neither being Whitworth form.

Tom

Reply to
Tom

All Associated engines used UNC. When I first got mine I made enquiries over the water and everyone confirmed it.

Keith Smigle is quite an expert, learn more at

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I was also led to understand that apart from 1/2 inch UNC, the tpi was the same as Whitworth but the pitch was slightly different.

Reply to
Pete Aldous

I don't think so, Pete. UNC never existed in that era.

Tom

Reply to
Tom

Tom,

I am only going on information from Keith and others but it is born out by the fact that I have just restored a 2 1/4 hp Hired Man and in the process, renewed every nut on the engine with Cadmium plated UNC nuts bought from Namrick and they fit the existing studs perfectly. Here is a quote from Keith:-

Pete~ Every engine that I own is UNC. The only problem we run into here in the US is some old engines use 1/2-12 UNC and others 1/2-13 UNC. I think Whitworth is mostly found on English applications IE: Autos etc.. I have never seen what I thought was Whitworth on an Associated engine.

Reply to
Pete Aldous

Interesting, Pete has come up with what I had assumed to be the case, but Tom puts a a fly in the ointment.

Tom, when was UNC introduced? What was the standard US system previous to that, or was there no standard?

In the back of my mind is the New-Way of 1916ish period, which I must tackle sometime. It would help me to know what thread system to expect.

Regards, Arthur G

fact that I have just restored a 2 1/4

plated UNC nuts bought from Namrick and

some old engines use 1/2-12 UNC and

IE: Autos etc.. I have never seen what I

Reply to
Arthur G

puts a a fly in the ointment.

that, or was there no standard?

sometime. It would help me to know what

the fact that I have just restored a 2 1/4

Cadmium plated UNC nuts bought from Namrick and

is some old engines use 1/2-12 UNC and

IE: Autos etc.. I have never seen what I

The Unified thread sytem was adopted by the US, Canada and the UK in 1949. Prior to that the US used the American National (NF, NC etc) that were developed from the Sellers 60º standard.

Tom

Reply to
Tom

That UNC & UNF will interchange with NF & NC and earlier thread forms is an aside. To be strictly kosher as a restorer, using UNC & UNF fasteners is easily detected my the purists, unless you machine off the identifiers..

Tom

Reply to
Tom

Aha!

Thanks Tom, you're a mine of information.

Regards,

Arthur G "Tom" wrote> That UNC & UNF will interchange with NF & NC and earlier thread

Reply to
Arthur G

Thanks for the information Tom.

Where can I obtain NC nuts and bolts from?

As a matter of interest I looked at all the nuts I got from Namrick and they do not have any markings on them.

Reply to
Pete Aldous

Send them around to everyone,I'm sure we can put some on :-))

Mart>> Pete Aldous wrote:

Reply to
Campingstoveman

Old machinery? NC nuts of the era you're interested in, only had a chamfer on one side.

Chances are that they are of chinese manufacture..

Tom

Reply to
Tom

Not wishing top be overly pedantic. TPI is the reciprocal of pitch. It's the thread angle that's slightly different. The other thing that's different is the AF size. This is especially so for earlier BSW nuts.

John

Reply to
John Manders

Hav you taken over from Roland, had to find my dictionary to check a few words :-))

Mart>> I was also led to understand that apart from 1/2 inch UNC, the tpi

Reply to
Campingstoveman

I do think the thread form is different, too..

Tom

Reply to
Tom

"Campingstoveman" wrote -had to find my dictionary to check a few

Pedantic or pusillanimous, Martin, what do you think? ;-)

Arthur G

Reply to
Arthur G

Ive put the book back now :-((

Mart> "Campingstoveman" wrote -had to find

Reply to
Campingstoveman

Tom The thread exchange reminded me of a real puzzle. At Internal Fire there is a Worthington-Simpson, vast vertical twin cyl cross-head two stroke semi-diesel, of about 150 hp. Some of the threads are American, others are BSP and the thread on the oil feed check-valves is 3/4 20tpi Whit form. Can't find it in any books but was able to pick up a s/h tap and die so it can't be that odd. Any ideas? Also the W-S was apparantly installed in 1926 which I reckon is after W-S stopped making engines so possibly a re-install. Absolutely zero information can be found on this engine. Does your extensive library have anything please? Pics at

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kind regards Roland

Reply to
Roland Craven

Gidday Roland, I've come across a lot of special threads on various engine fittings, it didn't seem to worry draughtsmen in the ole days to get the toolroom to work to their every whm. :-) On the otherhand firms like Rotherham used inhouse thread pitches and anyone who has worked on continental stuff knows that ISO Metric is a joke foisted on the world hoi polloi, whereas the cognoscenti use metric pitches not known to the ISO literati.

As for the W-S, pix aren't that flash for a good overall glimpse, but is it really a semi-diesel? Is there any pic of the maker's plate that could indicate it was a US design made under license? (Might account for the US threads. W-S seemed more steam orientated.

In the meantime, I'll have a wee delve.

Tom

Reply to
Tom

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