Contraction ruler markings question

Oct 11, 2006 26 Replies

Picked up a nice 24" Chesterman contraction ruler from eBay. It has fou



scales:



A CONT 1/96" K CONT 1/64" C CONT 1/120" M CONT 1/77"



Can any one help me out with what the letters are for? I assume it' for different alloys and varieties of cast iron (A for A.



Cheers



Mat


-- Myford Mat



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whoops that should have said: (A for Austentite?

-- Myford Mat

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Your figures seem to be per inch, the figures I have are per foot;

1/96 or 1/8 per foot Cast Iron Pipes 1/64 or 3/16 per foot Brass or copper 1/120 or 1/10 per foot Cast Iron beams & girders 1/77 or 12/77 near enough 5/32 per foot Bismuth, and it also says under cast iron "in thin breadth" and "in thick breadth" for 5/32 -but I've no idea what that is

Regards Kevin

Matt,

They are total waste of time and money, but out of the kindness of my heart I'll take them off your hands

AWEM

Swap him some kippers for it.

.

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

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In article , John Stevenson writes

It's the kippers he wants to check. They shrink something rotten under the grill.

More so under the kife and fork, I find. In fact, they seem to disappear altogether.

Regards, Tony

No intention of using it, I just like nice things - which obviously doe

not include kippers. So thanks for the offer, but I'll keep my ruler

Must be someone out there who can explain the letters - anyone?

Cheers

Mat

-- Myford Mat

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According to a 1935 Chesterman catalogue : "A letter is used to denote each degree of contraction. They are loosely allied to a particular cast material but contractions vary with different mixtures, are not to be taken too literally."

Your specific letters are: A = "cast metal" K = "Brass" C = "Steel or Iron" M = "Aluminium"

BTW What is the number of your rule?

Tom

I strongly recommend LOCKING them in a drawer when you're not using them. Preferably away from your workshop.

The consequence of using a contraction ruler (which looks perfectly normal) when you don't mean to are pretty dire...

BugBear

Yes you'd be thoroughly kippered. Best send them down to me for safe keeping.

AWEM

Thanks Tom - it's a 1958D

Cheers

Mat

-- Myford Mat

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Andrew and BB, you will be relieved to here that it is the onl

'24-inch' ruler I have, so it is unlikely to be confused with a rea one. But obviously I appreciate your kind offers of safe storage

-- Myford Mat

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As long as you have the cat out Tom, could you please look up my 24" Chesterman 1957D :-) Scales are: normal, C 1/120, D 1/60, and R 1/80. thanks.

I don't think my cat would put up with that kind of treatment ;-)

Regards, Tony

Hi Matt Unfortunately I haven't got a catalogue modern enough that lists that model. It would post-1961, when a 24" cost between 26 and 31 bob. The "D" suffix denotes a "D" shaped end to the rule.

Tom

Hi Roland Where're ya bin? Your rule, like Matt's, is too modern for me.:-( Not only the model, but the "R 1/80" is not listed in any I have. "O" is as far as I go. The "D" = "Double Steel"

Tom

I was constructing a "feline" reply when the wife suggested I would be better to let sleeping dogs lie ;-) Since you ask Tom: Eight weeks post-smoke damage from next door's fire. Still can't use any of the grinders and STILL dealing with crap cleaning Cos, arrogant complacent loss adjusters and absent decorators :-( At least I used a broker and he's on my side. Turns out the Ultimate Insurer is NU direct - HAWK..... SPIT!!! Quote me utterly P*****d O**.

ttfn Roland - on hol next week though :-)

Responded offlist due in regard for the list's delicate sensibilities...

Tom

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