On Sat, 15 Oct 2011 07:35:17 -0400, Suga Moto Soy

wrote:


Jimmy Suarez wrote:
can somebody tell what kind of thread is this?
http://www.signaturehardware.com/product8636

it is for an old fashined door knob spindle,the thicknes is 9/32 square
stock, and 20TPI,is there a nut or bolt made for this thing? Thanx

I don't know what the thread is, but those things are so soft it usually
doesn't even matter. They'll mush in anything.

I can't believe this Jimmy, nobody can give you an answer,I thought
some great machinists are posting here.I heve seen this type of door
knobs in many houses built from the 1900s to 1940s.

The thread in question is 3/8-20 UN. This is an obsolete thread that
probably is found only on door spindles and in door knobs today. It
may show up on other door hardware but AFAIK it is not used on
anything else. Taps are available to repair door knobs and levers. You
could make your own nut. I have made much door hardware for various
customers and all upper end hardware seems to use obsolete threads or
metric threads. You may be able to get away with an M10x1.25 nut or
bolt. 10 mm is nearly .014" larger than 3/8" (.375") but the pitch
m1.25 is less than .001" different than 20 TPI. I'm sure the
M10x1.25 nut would thread onto the spindle but it would be a loose
fit.
Cheers,
Eric