Wow, Home Depot....and plug style at that!
Wow, Home Depot....and plug style at that!
OK. Which thread tap size is correct? 5-44 or 5-48? I have already ordered a 5-44 and have not received yet. I guess I'l do a test tap in a scrap piece of aluminum and check.
Neither one is "correct " for the Copal shutter's cable release socket but the 5-48 will be closer.
Looking further in to this via google I found the assertion more than once that the Copal shutter may/usually/mostly has a straight rather than tapered thread cable release socket. Looking at a couple of my Copal shutters, this seems to be the case. Googling Copal shutter dimensions brings up drawings showing the cable release socket thread has a major diameter of 3.2 mm with a pitch of 0.5 mm. I have not been able to find an M3.2 x 0.5 tap. A pitch of 0.5 mm is very close to 50 threads per inch, 3.2 mm equals .126 inches. A number 5 machine screw has a major diameter of .125 inches. So the diameter is close and the pitch will be off a bit. I DON'T KNOW IF THIS WILL WORK OR NOT. (Sorry for the caps). May be worth a try since spares are apparently still available.
Now if you could find a 5-50 tap...
David
Your 5-44 will probably grab just fine but checking with a scrap of aluminum is a good idea. Also experiment with a chamfering tool on the beginning of the hole so that the cable release will go in straight . Good luck!
The difference between a .5 mm thread and a 48tpi thread is about .001” from peak to peak. 44tpi Will add .002” . A taper going into a straight thread doesn’t need to mesh perfectly as it will engage in only a couple of threads at most. Give it a try and see if you can make it work.
FWIW, McMaster-Carr sell JIS threading taps in addition to standard 3mm x 0.5mm metric taps. No 5-48 taps that I could find, though.
https://www.mcmaster.com/taps/jis-thread-taps/
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