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Mairead
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 26, 2006 - 08:13 am: | 
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I bought a 43.5 mm close-up lens for my Trip35. When I measure around the front of the lens, the measurement seems much larger. How are the measurements made? If this is a stupid question, I suppose I won'tget any replies!
But thank you all! |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 26, 2006 - 09:02 am: |
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43.5mm is the thread size. Technically you won't measure a dimension exactly 43.5mm. It is to the imaginary outside diameter. It is imaginary because the thread tips are deburred.
Henry |
Mairead
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 27, 2006 - 10:05 am: |
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Stupid or not, I got an answer. Thank you, Henry. I'm off to look up 'deburred'!
Mairead  |
John Shriver
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 13, 2006 - 07:39 pm: |
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Thread diameters are usually measured at the "middle" of the threads, half way between peak and valley.
--
John Shriver
http://john.shriver.home.comcast.net |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 14, 2006 - 10:44 am: |
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John, I think you are thinking of the pitch diameter. It is in the middle. The thread size (in both metric and US standards) is just a hair less than the nominal outside diameter. For instance, a 12mm bolt will fit in a 12mm drilled hole...but it'll be tight.
Henry |
