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How many major "standard" threads were in use in the thirties?

ASA, British standard, Whitworth Standard, Metric and?????????

Were they simply different sizes, or did any offer advantages of any sort, such as (possibly) deeper threads?

Pat

If you're really interested, there was an article in Skinned Knuckles in the past two years. I shoud have kept it, but have been trying to keep my life in order by cuting down on literature retention .

The short answer to the question is "mind boggling" "I had difficulty keeping track of the permutations



Regards


John Harley

Unknown!!!!!!!!!!!

USS (aka UNC coarse), UNF (aka SAE or fine), ACME, ASME, Naval Interference, Metric, BSW (British Standard Whitworth), BSF, BSP, NPT, BA (British Association). And who knows what goes on in Russia and China.

There are also systems for sheet metal, wood, lag and all those other screws and bolts.

Before World War I Packard chose to ignore the SAE convention and it was using things like 5/16-16 and 1/4-26 bolts all over its cars which is a nightmare. After the war they had to get their act together.

There is a whole discipline as regards the crown of the thread.

Of the above forgotten systems, the Naval Interference thread is long overdue for a revival. It is a self locker dating back to the days of steam power that would prevent some of the modern day failures taking place due to industry's preference to hire only the dumbest and most substance dependent labor. The number one priority in every hiring manager's brain is "It's not what you can do but how you are going to suck up."

Quote:

Russia went metric 1899 and the whole Soviet Union 1917 in the year of foundation.





[picture source: www.vintprom.ru]

Tim, one other thing: Employers are looking for someone who works cheap, and knowledge isn't very valuable these days.

Less commonly encountered are double, triple and quadruple lead threads. These are often in Acme thread on very special applications where a high rate of advancement per turn is desired. Anyone interested in such things and mechanically curious should really pick up a book like the attached.

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Quote:

Knowledge is very valuable these days. But companies don't want to hire it, they what to buy it ala carte. So much of what I do in my shop, could be done cheaper in house by my customers, but they don't want to pay the kind of wages it would require to hire a skilled person. It ends up costing them more in the long run.

And speaking of threads, I have a big pile parts in the shop right now that I'm machining in a 5 inch-10tpi thread.