Tripod mount

[Don Hoey]

I really did not believe it myself. Always thought camera threads were Whitworth. If I had not been playing with that head I still would. I don't know when the unified thread system was devised in camera history terms.
All I really know is that it was a committee decision to agree a form that would be common to America, Canada and Britain. I think there was a lot of American influence as it appears that eminent British engineers of the time thought it to be weaker than Whitworth.

Don

[yelvertoft]

This topic came up fairly recently on BF. To answer it, I checked my thread on tripod head with a set of thread gauges. I have a 1/4" Whitworth on at least one of my heads. A 1/4" UNC male thread will mate with a female bush in the base of a camera too but it's not a snug a fit as the 1/4"W thread gauge I tried, at least not on the camera I tried it on. I'll have to check the others (heads and cameras) to see.

Duncan

[Don Hoey]

This will be interesting Duncan. Before my post, and as I have no Whitworth, I looked in the spec for my D100 which says that the tripod mount is 1/4" ( ISO ).
I know that ISO recognise UNC but only as second choice to metric so took that as confirmation.

Thread guages are what I will believe.......... So look forward to your findings.

Don

[wolfie]

Not wishing to cause further confusion on this point, but on doing a search I find there are three conflicting thoughts, UNC, Whit and ISO. however a search on google did bring up the various specs for each thread i.e thread angle, pitch and threads per inch, but nothing conclusive.

So let us assume it's a Whit/UNC thread as the difference is not major and both appear to mate together, although not in perfect harmony.

Harry

[henryb]

Originally Posted by fishingdobbie

I know its a 1/4 inch diameter,what I am after is the thread type,when we used imperial measurements there was two types of thread ,one was whitworth, and I can't remember the other? Camera equipment never changed to millimeters which is a different thread also, ie 1/4 inch = 6.35, I am reasonably sure its whitworth, bert

Do you mean AF as in Amercan Fine ..hb

[wolfie]

I would agree on whitworth, the other imperial thread was British Standard Fine or BSF for short.
A further search as not brought anything definite regarding thread type, as most manufactures just them 1/4 or 3/8 inch camera threads.

I did find this, Quote. "But that is easier said than done: the Moskva-5 has a German screw tripod thread, but most modern tripods have English screw. There are adaptors and special plates available, but it's not ideal".

As the standard english threads are BSW & BSF it would seem that Whit is the answer.

[Don Hoey]

Originally Posted by wolfie

Not wishing to cause further confusion on this point, but on doing a search I find there are three conflicting thoughts, UNC, Whit and ISO. however a search on google did bring up the various specs for each thread i.e thread angle, pitch and threads per inch, but nothing conclusive.

So let us assume it's a Whit/UNC thread as the difference is not major and both appear to mate together, although not in perfect harmony.

Harry

This is under investigation, but because of the holidays and the shut down of engieering works where the necessary kit to positively confirm resides, will have to wait until into the New Year.
I know UNC fits because I have tried it. However yesterday I came across a sample of British manufacture from the 50's that may well be Whitworth. That has a slightly different form from a unit from Japan circa 1990's that matches UNC.

ISO refers to whether the thread conforms to a standard, and is not a form in its own right.

UNC as a stardard ( ISO ) thread appears to have come out just after the war as a response to the variety of American, British and Canadian threads in common use and the desire to standardise. The odds are that its choice was therefore heavily influenced by America.

That date stamp does suggest Whitworth but we will have to wait and see.

Don

[colpurps]

Originally Posted by fishingdobbie

Am I correct in thinking that the screw thread of the tripod mount is 1/4 BS WHITWORTH , cheers,Bert

Yes it is definately. I have a massive collection of taps and dies etc for most threads going back years should you have any problems, and a screw-cutting lathe and all the thread data you would ever need. Also a heap of nuts and bolts etc. Drop me a line if you need any help, I was a design engineer in the past, so I might be able to help with any adapters. Happy new year.

[fishingdobbie]

After having a good search, I have come to the conclusion that only the actual manufactures know what thread gauge they use. In the states the resellers mostly describe the bush as ¼ inch x 20 unc, in the UK they describe it as ¼ inch Whitworth. Bert

[colpurps]

Hi
I am glad you are happy with your situation but these two threads are not the same. BSW has a thread angle of 55 degrees while the UNC has a thread angle of 60 deg. OK, you can get away with interchanging if you are only using parts which are under too much stress, but, your head may shake loose if you walk with your camera attached in the field. That could be very expensive, it happened to me. The tapping drills for these threads show how different they are, full details are on this site: http://www.britishfasteners.com/threads/unc.html
Take care.