Thread standards: a link

Thanks Nick - a useful link now on my engineering favorites list !

AWEM

I note that it claims that camera tripod threads are UNC... This is very wrong!

Mark Rand RTFM

Quite right - and an insult to Sir Joesph's memory! It's not difficult to get it right and it makes me worried about any other information.

c

If it`s data you want,have a look at this lot.Threads are near the bottom of the list.

Mark.

It may be technically wrong, but most people specify tripod threads as

1/4" UNC -and they do fit. In fact, we fit 1/4" UNC inserts for tripod mounts on some cases at work -they are the only size available.

Regards Kevin

Like the cycle threads ??

.

Pray enlighten us then, good fellow.

Chris

Camera tripod threads are Whitworth. Different included angle, different root, different crest. Saying that they're UNC is like saying 0BA is the same as ISO M6 coarse or that 2000 is the start of the current millennium.... Wrong

Mark Rand RTFM

Close but no cigar then?

Chris

He seems to have got the angles right, just got the pitches wrong and used the wrong units :-)

Mark Rand RTFM

Could be quite serious when you fit the high powered winder to the camera, use the flogging spanner to get a good grip on the tripod and then the vibration shears the ill-fitting threads.

Mark Rand RTFM

...And I love the idea of converting fractals to mm. However, that's just a minor mis-translation, and the information is indeed very useful.

One thread not on the list but very useful (admittedly only to those involved in the field, but that applies to many of the others) is the RMS (Royal Microscopical Society) standard thread for microscope objectives. This is approximately 0.8" x 36 tpi Whitworth form thread, the precise details (with maximum and minimum tolerances) are set out in BS 7012 part 4 and ISO Standard 8038 (1985). Until a decade or two ago, virtually every microscope (not just those made in the UK, but those from Germany, Eastern Europe, Asia etc.) all used this thread form. More recently there has been a tendency for makers to use larger threads, mostly different for each manufacturer, which no doubt helps keep up sales of the maker's own parts!

David