ORIGINAL: jrf
The conversion is approx 25.35 mm to the inch.
I'm curious to find out where you got 25.35mm to the inch. If you check in your college Chemistry, Physics, or Calculus book, it's exactly 25.4mm to the inch. If you punch 1" into your scientific calculator and ask it to convert to millimeters, you will get exactly 25.4mm.
If you go to [link=http://www.convert-me.com/en/convert/length]Convert-me.Com[/link] or [link=http://www.digitaldutch.com/unitconverter/]WWW Unit Converter[/link] and enter 1 inch, you will get exactly 25.4mm.