<div dir="ltr">Joe,<div style>If you counted <i>51</i> threads per inch, that would be 2 X 25.4, which would work out to .5 mm, which worked for me. Some old screws really are metric.</div><div style>--John Ashcraft</div></div> <div class="gmail_extra"><br><br><div class="gmail_quote">On Sat, Feb 23, 2013 at 2:25 PM, Joseph Garrett <span dir="ltr"><<a href="mailto:joegarrett@earthlink.net" target="_blank">joegarrett@earthlink.net</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Ron said:<br> "I worked out the numbers, and these are 3-56, a standard size"<br> <br> Ron,<br> For all practical purposes, yes that is what my gauges tell me.....er<br> sorta.<G> Honestly, it did not occur to me to "do the math" conversion!<G><br> If the 4.5mm threaded hole was more than 1/2 inch, it would start to bind<br> with a 3-56. At least that's what my gauges are telling me.<G> However, in<br> this application, where the threaded material is less than 1/16", it's not<br> an issue.<br> There still remains, tho, what the heck all of those NOS plates/screws, I<br> have, are? As near as I can calculate, the thread count is around 52 tpi! I<br> don't know of any "standard" that fills that bill. Go figger.<br> Thanks for your help and enlightenment.<G><br> Best,<br> Joe<br> <br> <br> Joe Garrett, R.P.T.<br> Captain of the Tool Police<br> Squares R I<br> <a href="http://gpianoworks.com/" target="_blank">http://gpianoworks.com/</a><br> <br> </blockquote></div><br></div>