10-30 screw thread?

MrTube

MrTube

Well-known member
Just curious if anyone has ever heard of a 10-30 screw thread used in the 1920s or 30s?

Its definitely not 10-32 or 10-24.
 
Charlie Stephens said:
No, but is there any chance you are looking at something metric or whitwortth (sp?)?
Charlie Stephens
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I suppose its possible.
I have not personally measured them but I'm told nothing SAE or Metric matches. Was Whitworth common in the US during that time?

These are screws used on 1920s-1930s GE refrigerators like the one in my Avatar. So far no one can figure out what they really are. a 10-32 works but is very tight due to the slight difference in threads.

GE was based in Schenectady NY at the time if it helps.
 
mass A man said:
Could it be an "interference fit"? Sometimes this was used so as a lock washer was not needed.
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Don't think so.
We have the original screws which are made from I think monel or bronze can't remember. Measuring the actual screw shows a 30 tpi and they thread in pretty nice.

The 10-32s work for the most part, just a little tight going in. But it left us wondering what kind of thread it was.
 
To keep it on topic, information is taken from "Mechanic's Vest Pocket Reference Book", compiled by John H. Wolfe, Sc.D., Supervisor, Apprentice School, Ford Motor Co., Dearborn.

#10 screws are listed in 30, 32, and 24.

There are now-obsolete thread counts for many sizes of bolt and screw.
Taps and some fasteners in oddball sizes can generally be found at places like MSC Industrial Supply.
 
Bruce Lancaster said:
To keep it on topic, information is taken from "Mechanic's Vest Pocket Reference Book", compiled by John H. Wolfe, Sc.D., Supervisor, Apprentice School, Ford Motor Co., Dearborn.

#10 screws are listed in 30, 32, and 24.

There are now-obsolete thread counts for many sizes of bolt and screw.
Taps and some fasteners in oddball sizes can generally be found at places like MSC Industrial Supply.
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Excellent information.
Thank you Bruce!
 
Ford was using tighter tolerance threads on the A.

Maybe this is a case of tighter tolerance threads. Would it make sense for the application?
 
The companies like Starrett and Brown&Sharpe who made precision tools would purposely use odd thread per inch components so they're tools would not be easily copied or altered.
 
KR500 said:
The companies like Starrett and Brown&Sharpe who made precision tools would purposely use odd thread per inch components so they're tools would not be easily copied or altered.
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This and what was true about gun screws too - ive ran into that problem before...
 
MrTube said:
Just curious if anyone has ever heard of a 10-30 screw thread used in the 1920s or 30s?

Its definitely not 10-32 or 10-24.
Click to expand...

I just stumbled on this thread today - I use 10-30 screws all the time. I have them in 1/2" and 3/4" cheese head. These fit on a LUDLOW TYPOGRAPH machine built in the early 1900's. From what I can find these were a common thread size in the early 1900's but were discontinued when the 10-32 and 10-24 came into use. I also use some 1/4X24 screws that were of the same era.
 
FYI ACE hardware now stocks a few of those tan colored bins of gun screws in all sorts of oddball threads.
 
Another FYI!
Whitworth threads are the same pitch as SAE up to 1/2" except that it has a thread form of 55 degrees, while SAE is 60 degrees. Also worth noting is that there is no such thing as a Whitworth thread smaller than 1/4". Anything smaller we see these days has been created by who knows who sometime since. It was intended that BA be used for smaller sizes.
Whitworth was the world's first standardised thread system.
https://en.wikipedia.org/wiki/British_Standard_Whitworth
 
I also use some 1/4X24 screws that were of the same era.
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Are you sure that they're 1/4" and not #14?
14-24 is an obsolete A.S.M.E. thread w/a diameter of .242"
 
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