"Ed Huntress" wrote in message
...


wrote in message
...

On Oct 16, 10:12 pm, "Ed Huntress" wrote:

I checked mine with a loupe; it's definitely 18 tpi.

--
Ed Huntress


Yours may be 18 tpi, but the standard is 20 tpi.

http://houseofantiquehardware.com/s.nl/it.A/id.3517/.f

Dan

Why did you clip out the reference to 3/8 x 18s, Dan?

Besides the Lockwoods, here are some other manufacturers who used 18 tpi
threads:

http://www.robertbrooke.com/door/loc...n_russwin.html

http://www.robertbrooke.com/door/locksets_marks.html

If you look around, you'll see that there appear to have been three
standards for 3/8" threaded door knob spindles: 16 tpi, 18 tpi, and 20
tpi.

--
Ed Huntress



To be fair, the original poster specifically stated that the spindle he was
looking at was 20tpi.

There are indeed three standards:
"Standard spindle thread is 20 TPI. Also available in 16 TPI ,#2600S
(Sargent) &18TPI, #2600L (Lockwood)."

I repair, refinish, rework about a dozen vintage mortise locksets each year.

It may be a regional thing, but here in Chicago, I have never seen anything
but the 20s.

I can say with certainty, however, that these threaded spindles suck. The
average homeowner performs less maintenance on his doorknobs than he does on
his roof. This, combined with the small area of thread engagement and the
fact that most of these things are made out of some metallic colored hard
cheese, means that it is only a matter of time before they fall apart.

Go get yourself some knobs with square holes and some threaded hole
spindles.



Paul K. Dickman