Source for M4-0.75mm set screws?

[Highpower]

I need a couple of M4 set screws with a 0.75mm pitch. (10mm length)

Any suggestions of where I might find some? Google failed me...

[jlevie]

http://www.mcmaster.com/#set-screws/=qiuygy The standard thread pitch is 0.70, which is what I think you need. But otherwise it was dead easy to find them.

[Highpower]

Yes. I can find 0.70 pitch all day long as well. Unfortunately I actually do need 0.75mm pitch screws. So maybe it will be dead easy for you to find them too?

[ironmonger]

I couldn't even find that thread listed... checked out course, fine and extra fine metric tables.
What is it for?

I know it's nuts, but 8-32 is .007" larger in major diameter and the .75 mm pitch comes out to 33.8 threads per inch. For your length thats about .010" discrepancy in overall thread length for .75mm pitch to 32 TPI

Regardless, I would be curious to see what happens if you tried a 8-32 screw...

paul

[Mike Nash]

A BA No. 3 is closer at 4.1mm x 0.73mm

I couldn't find anything closer either. M4.5-0.75 is listed as a standard.

http://www.gewinde-normen.de/en/ba-thread.html

[ironmonger]

A BA No. 3 is closer at 4.1mm x 0.73mm

I couldn't find anything closer either. M4.5-0.75 is listed as a standard.

http://www.gewinde-normen.de/en/ba-thread.html

Nice chart!
thanks

paul

[lakeside53]

Try a French web site. Anything metric that is a "standard" but not available is usually French

[EddyCurr]

Actually, it may be a pre-ISO German or Italian fastener
conforming to DIN specs.

Some discussion here suggests it may be necessary to make
your own replacement(s). Looks as though taps/dies can be
located.

.

[Highpower]

Try a French web site. Anything metric that is a "standard" but not available is usually French

LOL. You nailed it lakeside!

This is for an Arpo force/tension gauge that was made in France - circa 1958.
I was surprised to find that a M4-0.50 thread exists as well. http://www.tap-die.com/contents/en-u...tric_taps.html

Oddly enough my Vermont American (China) tap & die set contains both M4-0.70 and M4-0.75 sizes. I chased the threads in the gauge housing easily with the 0.75 pitch tap. Finding replacement screws however is not coming so easily....

Edit to add:

Regardless, I would be curious to see what happens if you tried a 8-32 screw...

Paul - It goes in 1-1/4 to 1-1/2 turns and stops. No joy.

[lakeside53]

Yep.. try finding Peugeot 504 (French) carb screws... M5x0.7 (or was it 0.75?)

Oh, just tap them out to 0.8!

[Jaakko Fagerlund]

If it fits, I would just drill & tap M5 there, or try first tapping it with regular M4. Or just drill larger, plug it and make a completely new hole in the plug (or use a Helicoil or something).

[haroldmulder]

I played around the web and could not find a source of set screws however there were sites that sold Tap and Dies for this size so if you really want a set screw with this thread maybe you could make your own.
Here's a die for sale on Amazon

Good Luck
Harold

[Rustybolt]

Merde!

[Highpower]

Merde!

Short, sweet and à propos. I like it!

Similar to Jaakko's recommendation, another member suggested to me to try running a 'standard' 0.7 screw through a 0.75 die. I think i will try that first as it would leave the threads in the gauge original. Failing that I will probably just re-drill and tap to M5. I was trying to keep things as original as possible even though that isn't really practical. I'm off to one (or two) of the big box 'hardware' stores that usually has an isle full of empty small fastener drawers...

[EddyCurr]

If going the route of re-threading an existing M4 set screw,
wouldn't a fine pitch M4 x 0.50 provide more material to cut
the coarse 0.75 pitch into than the 0.70 will ?

Expediency and patience probably determine how much time
to devote to resolution. Always seems a shame to rush to
modify a vintage item - in this case by tapping to a new size.

What about making a replacement w/ correct pitch. The hex
socket is beyond me to suggest, but would a slot drive on the
end work in your application?

Brownells does not appear to list 0.75, but this size appears in
threads related to firearms in NA. Also, there may be Euro sites
for various interests where folks may be able to provide a source
for a used/unused replacement.

Bear in mind the different nomenclature: 0.75 here is 0,75 elsewhere.

If you succeed in locating a source, consider posting back to this thread.
I know I will be interested in learning where such items might be found,
others now or later may likewise wish to know.

.