mixed threads...
 

While all of the threaded parts on the P08 were cut to the English Whitworth standard, several threaded parts on the accessories were made to some other standard. On some blueprints certain screws are labled Gew 4mm and a symbol for diameter. Gew, I assume, stands for "gewinde" which means thread.


I am actually quite surprised by the mixing of thread types and I assume that it was due to war time pressures (WWI).


I am unable to find any reference to the pitch of those metric threads, does anyone know the standards used, or know the likely pitch of metric fasteners in the early 1900's...


Thanks FGR

Re: mixed threads...
 

fgr,


One of the reason for the mixing of the threads is that DWM purchased some of the equipment from Pratt & Whitney (I think that is the company) and the machines produced threads to English standards. This also seems crazy to me for a metric country to use a differnent thread type.


Marvin

Re: mixed threads...
 

FGR, contact Hugh Clark. I believe he can help you.

Re: mixed threads...
 

Wish tread size is it you would like to know.

I have copies of both 1900 and 1906 swiss prints so i can look it up.


Regards HÃ?Â¥kan



http://www.vapensmedjan.com

Re: mixed threads...
 

Metric country.


As far as i know the metric standardisation wasent started 1900.

The SI system came some years later.


Regards HÃ?Â¥kan



http://www.vapensmedjan.com

Re: mixed threads...
 

If you measure the outer diameter of the thread and the distance between the threads (I.D. would be helpful) I can give you the thread type and tolerance.


Good luck

Re: mixed threads...
 

I have one that is 4mm exactly OD and it looks like 32TPI...

I have found no reasonable match to this thread in any of my engineering texts... so any guesses would be welcome. FGR

Re: mixed threads...
 

Frank,


The grip screws apparently were made in two sizes, I don't know when, where, how or who. They were made in 3/16"x32tpi, and in 4.5mmx.8 thread pitch. I just bought the set of Luger dies and taps that Sam Buscemi had for sale. According to him the 4.5x.8 mm is a rare configuration. If any one needs their threads renewed on the frame or screws of their gun, I can do this now. I hope to be able to furnish target style barrels sometime in the distant future.

Re: mixed threads...
 

Hugh; Make sure when you identify your new tap and dies that you let people know they are the English Standard Whitworth configuration which is neither metric or SAE standard as we know it.

Source for BSW, BSF and BA fasteners
 

I can't vouch for the company but The Rolls Royce Owners Club lists a source for Whitworth and other strange fasteners the English used over the years. I assume they still exist and the following is current:

British Tools and Fasteners

2030 Andre Avenue

Los Osos, California 93402

Voice 800 587-0475

Fax 805 528-0358

e-mail boltnut@msn.com

http://www.mrcybermail.com/machine_tool_parts/.

Corrrected URL. Sorry.
 

My eyesight must be failing. The correct URL is:

http://www.mrcybermall.com/machine_tool_parts/