<div dir="ltr">My 1930s house used 5/16" x 28tpi.<div><br></div><div>Even among local antique store junk drawers that isn't common.</div><div><br></div><div>I was able to find 5/16" bolts with 28tpi threads that screwed perfectly into the holes, but somebody with more free time than I have would need to cut the bolt into set-screws and machine a screwdriver slot into them.</div><div><br></div><div>So.... good luck with that. My problem remains unsolved waiting for another day.</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Mar 3, 2017 at 7:35 PM, David Scheidt <span dir="ltr"><<a href="mailto:dmscheidt@gmail.com" target="_blank">dmscheidt@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I have a number of door knobs that need set screws to hold them to<br>
their spindles. (Square threaded spindles in mortise locksets.) The<br>
normal size of these is 1/4-20 or rarely 5/16-24 or even more rarely<br>
1/4-28. The existing screws are 28 tpi, with a major diameter of<br>
0.280. That's no screw thread I know of, but I have a house full of<br>
them (identical glass door knobs, presumably original to the house,<br>
circa 1925.) so it must be something.<br>
<span class="HOEnZb"><font color="#888888"><br>
<br>
--<br>
David Scheidt<br>
<a href="mailto:dmscheidt@gmail.com">dmscheidt@gmail.com</a><br>
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