Jimmy Suarez wrote:

"Suga Moto Soy" wrote in message
...

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

Well, mine was built in 1924, but assuming it was a long-time
standard, the thread is 18 tpi (0.072" pitch) (Starrett thread gage)
and the major diameter of the threads is around 0.375" (Starrett
mike). The spindle is a little worn from old age and use, so I'll let
you guess at what nut might fit. It looks to me like a 3/8 x 18. I
don't believe that's a standard; UNC is 3.8 x 16 and UNF is 3/8 x 24.

I'd double-check that 20 tpi; it's close, but no cigar on the
spindles on my doorknobs.

Sorry about the delay,computer crashed,I measured all the spindles(6)
that I've found in my house(built the 1930s)and it looks to me that
they are all 20tpi,now I have to find some 3/8x30 bolts or nuts.I
found on a site 9/32x20 british threads-9/32 square stock is the size
of the spindle.My next question is how do you thread a square rod
without breaking the die?


A couple of replies gave sources for the ready made spindles such as

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

Who list 20tpi items and other pitches. Also you're not looking at a
9/32"x 20tpi thread but a 3/8" x 20tpi because 9/32 is the AF size of
the spindle and you want the diameter which will be the distance across
the points of the square shaft.