Auto Yashinon 5cm f2 Filter Size?

[PGraham3]

Howdy, APUG!
I have a few AUTO YASHINON 5cm f2 m42 lenses from the early 1960s and I've been trying to figure out what exact filter size they have. I found one source in Japanese that apparently says it's 46mm, but I'm not exactly sure. I'd hate to buy the wrong filter-size.
Does anyone know what filter size this lens has? Thanks a bunch!
-Paul

 

[macfred]

According to this page filter size should be 46mm http://pakira3.sakura.ne.jp/wp/?p=18856

Edit: I guess it's the same source you mentioned above ...
What about using a calliper ?

 

[monst]

Can you not measure it?

 

[PGraham3]

Yeah, that was the one source I had found, which appears to be correct. I roughly measured, and 46mm appears right, but it was also fairly close to 47mm. So just trying to make sure. Worst case scenario is that I spend $5 on a 46mm UV filter and it doesn’t fit. Will give it a go.
Thanks for commenting!
-Paul

 

[AgX]

A basic caliper only costs a few dollars and is very useful for other tasks too.
I admit that measuring female threads is not that simple, but even without a table with thread core diameters one should be able to establish a filter size.

 

[John Koehrer]

Your caliper's on the money, on the inside of the thread, your can't get to the full measurement; it's about .5mm off.
This is true of any filter size.

 

[PGraham3]

46mm right on the money! Filter fits perfect. Thanks, fellas! Much appreciated!
-Paul