<div style="margin: 0in 0in 0pt">What you need is a razor saw and a miter box like these sets shown here. These are very common inshops that cater to model railroaders especially
<font color="#606420">http://www.micromark.com/SearchResult.aspx?deptIdFilter=0&searchPhrase= miter+box</font> The slots in the box will guide your saw so it cuts straight and vertical. Clamp a stop block to the right of your cut the length you want your nuts to be. They will all be cut uniform. You can also get by with a shallow ‘L’ shaped block and just the razor saw. HTH and good luck. </div>