Perciuliar American threads trivia question

There are three separate ISO fine threads for, at least, 12mm:-

1mm, 1.25mm, 1.5mm Plus the coarse thread at 1.75mm

Mark Rand RTFM

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Mark Rand
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Why does model making need BA threads? The Americans use there numbered

Because most of them have coarse threads and look quite inappropriate; also the various members of these series are too far apart. The 10% steps in the BA series gives a very fine degree of choice.

Have you actually *used* BA threads? I ask because most US model engineers have no idea what they are, or at least never get to se them. Their loss.


-- David Littlewood

Yes I have used BA.

If you are making a scale model why change the tread angle so much

60Deg is close to 55 than 47.5?

Using metric coarse as a comparison

0 - 10BA is 11 thread sizes with, OBA at 6.0OD x 1mmP 10BA at 1.7OD x 0.34mmP Pitch reduces in .9 steps.

M6-M1.6 is 8 threads with, M6 at 6mmOD x 1mm pitch, M1.6 at 1.6mmOD x0.35mmP Average pitch reduction 0.86 steps

Doesnt look that big a change and thats without using fine series.


-- Steve Larne

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Steve Larner

Thats buggered the west coast line over power cable stanchions then :-)


Reply to
Steve W

Nothing to stop Railtrack's subbies using _lots_ of them :-)

Mark Rand RTFM

Reply to
Mark Rand

You generally won't get far asking for them in a UK bolt supplier ;-)


Reply to
Tim Leech

Since this is a .uk group, I guess you get to call those threads peculiar. ;)


Michigan, USA.

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