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Machine Screws in imperial size - in France?


Ian

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I need four machine screws - 0.25" (20UNC) x 1.25"/1.5", with countersunk heads. They're for a router.

Does anybody know if these are available in France, or will I have to have them sent from the UK? And if so, any idea who wou;d do supply them in such a small quantity?

Thanks

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The ISO metric thread and the Unified inch thread
have the same form. The two thread systems differ
only in choice of diameters and pitch lengths for
standard sizes. Thus, it is possible for metric
and inch threads to be compatible if the tolerances
for the two threads overlap.

A comparison of pitch lengths for both Unified
and ISO metric screw threads indicates that the
following seven combinations are the only ones
potentially compatible:

Threads
Inch mm
72 0.35
64 0.40
56 0.45
44 0.60
36 0.70
32 0.80
20 1.25

A comparison of pitch diameters for these pitch
lengths indicates the following six combinations
are potentially compatible:

Unified* Metric**
0.73 - 72 1.8 x 0.35
.086 - 56 2.2 x 0.45
.099 - 56 2.5 x 0.45
.164 - 36 4.0 x 0.7
.190 - 32 5.0 x 0.8
.3125 - 20 8.0 x 1.25

*UNIFIED The first number indicates major
diameter in inch unit, and the second number
indicates the number of threads per inch.
**METRIC The first number indicates major
diameter in millimeters and the second number
indicates the pitch (distance between thread
centers) in millimeters.

While it is not recommended to combine a metric
and inch thread, the combinations noted above
show that the ISO metric and unified threads
are very similar. Either series could satisfy
the needs of a general purpose screw thread
system for most fastener applications.

http://www.allmetalcorp.com/htm/pg8_5_12.htm

 

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* Clarksinfrance - thanks for the idea. Yes, it's for the base plate - I'm building a router table. Next time I'm in Leroy Merlin, I'll have a look, but I suspect your Bosch router may be metric - my circular saw is.

* Gluestick, interesting. Didn't realise metric was so similar to something as old-fashioned as imperial. Not enough for me this time though - my 1/4" shank falls between the last two possibles.

I've found a UK source who will ship them to France, so I think I'll just go ahead - it's about as cheap as shipping to a UK address, so save the hassle and cost of forwarding.

Thanks for the help - much appreciated

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[quote user="Gluestick"]

[quote user="Ian"]- my 1/4" shank falls between the last two possibles.

[/quote]

In engineering terminology, Ian, I believe that's called Murphy's Law!

[:D]

[/quote]

...story of my life.....

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*Clarksinfrance - couldn't find anything in LM with a UNC thread, hélas.

Ordered a dozen from a company called Namrick, postage was only £4 - they arrived today. Very helpful people, can recommend them for this sort of thing.

Cheers

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