"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?