kind of thread is this
 

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

kind of thread is this
 

On Thu, 13 Oct 2011 15:56:00 -0400, 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

Old enough to be its own standard, for one -- the house that my maternal
grandmother lived in was built in 1905 and had that style of hardware in
it. 1905 wasn't quite Before Standardization, but it was certainly at a
time when standards weren't terribly prevalent.

Now I'm kinda curious -- and I don't know the answer!

--
www.wescottdesign.com

kind of thread is this
 

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've seen those before on many occasions in the UK. If your stock is
9/32 AF then that would give 0.398" across the corners if perfect but
they're usually rounded, I would hazard a guess and look at 3/8" BSF
which is 20 tpi. I understand Whitworth was used in the US for a while
but BSF only came about in the early years of the 20th century, BSW
having become a standard around the mid 19th century.

kind of thread is this
 

On Oct 13, 1:56*pm, 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

That's what lathes are for. Had a couple like that on the French
doors at my parents' house, most of the rest in the place were a
little smaller and segmented diagonally so that the knob setscrew
would expand them in the latchset's square hole. Never had any
trouble with knobs pulling off with that sort, the French doors' knobs
were always loosening up. I think those spindles were hard and the
setscrews wouldn't bite in. Glad to know there's replacement parts
now, the place was built in the mid-20s and regular hardware stores
had nothing when we went looking, knobs or spindles.

Stan

kind of thread is this
 

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.

No machinists here anymore?
 

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.

No machinists here anymore?
 

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.

Its not the quality of the machinist..but the quality and variability of
the work piece in question.

Gunner

"In the history of mankind, there have always been men and women who's goal
in life is to take down nations. We have just elected such a man to run our
country." - David Lloyyd (2008)

No machinists here anymore?
 

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

No machinists here anymore?
 

"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

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.

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.

--
Ed Huntress

No machinists here anymore?
 

Ed Huntress 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

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.

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.

I suggested 3/8" BSF which is 20 TPI but the OP doesn't seem to have
responded to any poster regarding their comments. If the OP is in the US
then BSF won't be that common unless they're next to gunner's motorbike
but for me my neighbour has quite a selection of BA, BSF, BSW, BSP, and
more recently UNF and UNC, and staggeringly a few metric, I also know a
guy that would have many such spindles from various periods so could
measure if required.

The period of manufacture would be of some use in pinning down standards
or not. I recently repaired a ceiling light, most likely of Dutch
manufacture in the 19th century, and the main thread holding it together
appeared to be M10.7 x 1.5. From the design with solid arms no provision
had been made for gas or electric so candles were the original light and
I reckon it dated from the first half of the 19th century. The 1.5 mm
thread pitch would be 17 TPI, which I have never seen anywhere , but
1.5mm pitch might make sense. IIRC at that date no real standards
existed, BSW coming in around the mid 19th century in the UK, so I
expect the threads were produced to suit in the factory which certainly
seems to be supported by the other mish-mash of threads else where in
the items. In the end I single point cut the main suspension rod thread
at one end to suit the female piece it mated with and the non-visible
end I fitted with a M10 helicoil.

No machinists here anymore?
 

"David Billington" wrote in message
...

Ed Huntress 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

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.

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.

I suggested 3/8" BSF which is 20 TPI but the OP doesn't seem to have
responded to any poster regarding their comments. If the OP is in the US
then BSF won't be that common unless they're next to gunner's motorbike
but for me my neighbour has quite a selection of BA, BSF, BSW, BSP, and
more recently UNF and UNC, and staggeringly a few metric, I also know a
guy that would have many such spindles from various periods so could
measure if required.

The period of manufacture would be of some use in pinning down standards
or not. I recently repaired a ceiling light, most likely of Dutch
manufacture in the 19th century, and the main thread holding it together
appeared to be M10.7 x 1.5. From the design with solid arms no provision
had been made for gas or electric so candles were the original light and
I reckon it dated from the first half of the 19th century. The 1.5 mm
thread pitch would be 17 TPI, which I have never seen anywhere , but
1.5mm pitch might make sense. IIRC at that date no real standards
existed, BSW coming in around the mid 19th century in the UK, so I
expect the threads were produced to suit in the factory which certainly
seems to be supported by the other mish-mash of threads else where in
the items. In the end I single point cut the main suspension rod thread
at one end to suit the female piece it mated with and the non-visible
end I fitted with a M10 helicoil.

================================================== =============

When I hear stories like that, I always wish I could be there when the next
handyman tries to repair the custom thread. g

My ancient plumbing contains a few brass parts that I've had to
custom-thread, but I don't think it will all last before I have to replace
the whole works. I've already succumbed to plastic pipe in place of oakum
and lead on my cast-iron waste pipes. so the end is near.

The spindle on one of my tub faucets is a piece I turned from the bronze
propeller shaft of a 50' commercial fishing boat, with the splines cut by
cranking the feed handle on my lathe, with a lathe bit clamped in my milling
attachment.

That's why my wife calls me a cheapskate.

--
Ed Huntress

No machinists here anymore?
 

"David Billington" wrote in message
...
Ed Huntress 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

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.

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.

I suggested 3/8" BSF which is 20 TPI but the OP doesn't seem to have
responded to any poster regarding their comments. If the OP is in the US
then BSF won't be that common unless they're next to gunner's motorbike
but for me my neighbour has quite a selection of BA, BSF, BSW, BSP, and
more recently UNF and UNC, and staggeringly a few metric, I also know a
guy that would have many such spindles from various periods so could
measure if required.

The period of manufacture would be of some use in pinning down standards
or not. I recently repaired a ceiling light, most likely of Dutch
manufacture in the 19th century, and the main thread holding it together
appeared to be M10.7 x 1.5. From the design with solid arms no provision
had been made for gas or electric so candles were the original light and I
reckon it dated from the first half of the 19th century. The 1.5 mm thread
pitch would be 17 TPI, which I have never seen anywhere , but 1.5mm pitch
might make sense. IIRC at that date no real standards existed, BSW coming
in around the mid 19th century in the UK, so I expect the threads were
produced to suit in the factory which certainly seems to be supported by
the other mish-mash of threads else where in the items. In the end I
single point cut the main suspension rod thread at one end to suit the
female piece it mated with and the non-visible end I fitted with a M10
helicoil.

The spindles are usually 20 pitch, Ed must have some oddballs.
The thread form doesn't matter much because so little of is left on the
corner of the spindle.



Paul K. Dickman

No machinists here anymore?
 

"Paul K. Dickman" wrote in message ...


"David Billington" wrote in message
...
Ed Huntress 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

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.

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.

I suggested 3/8" BSF which is 20 TPI but the OP doesn't seem to have
responded to any poster regarding their comments. If the OP is in the US
then BSF won't be that common unless they're next to gunner's motorbike
but for me my neighbour has quite a selection of BA, BSF, BSW, BSP, and
more recently UNF and UNC, and staggeringly a few metric, I also know a
guy that would have many such spindles from various periods so could
measure if required.

The period of manufacture would be of some use in pinning down standards
or not. I recently repaired a ceiling light, most likely of Dutch
manufacture in the 19th century, and the main thread holding it together
appeared to be M10.7 x 1.5. From the design with solid arms no provision
had been made for gas or electric so candles were the original light and I
reckon it dated from the first half of the 19th century. The 1.5 mm thread
pitch would be 17 TPI, which I have never seen anywhere , but 1.5mm pitch
might make sense. IIRC at that date no real standards existed, BSW coming
in around the mid 19th century in the UK, so I expect the threads were
produced to suit in the factory which certainly seems to be supported by
the other mish-mash of threads else where in the items. In the end I
single point cut the main suspension rod thread at one end to suit the
female piece it mated with and the non-visible end I fitted with a M10
helicoil.

The spindles are usually 20 pitch, Ed must have some oddballs.
The thread form doesn't matter much because so little of is left on the
corner of the spindle.

It appears that 3/8 x 18 was one of the old standards:

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

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

--
Ed Huntress

Paul K. Dickman

No machinists here anymore?
 

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

No machinists here anymore?
 

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

No machinists here anymore?
 

Ed Huntress wrote:


"David Billington" wrote in message
...

Ed Huntress 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

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.

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.

I suggested 3/8" BSF which is 20 TPI but the OP doesn't seem to have
responded to any poster regarding their comments. If the OP is in the US
then BSF won't be that common unless they're next to gunner's motorbike
but for me my neighbour has quite a selection of BA, BSF, BSW, BSP, and
more recently UNF and UNC, and staggeringly a few metric, I also know a
guy that would have many such spindles from various periods so could
measure if required.

The period of manufacture would be of some use in pinning down standards
or not. I recently repaired a ceiling light, most likely of Dutch
manufacture in the 19th century, and the main thread holding it together
appeared to be M10.7 x 1.5. From the design with solid arms no provision
had been made for gas or electric so candles were the original light and
I reckon it dated from the first half of the 19th century. The 1.5 mm
thread pitch would be 17 TPI, which I have never seen anywhere , but
1.5mm pitch might make sense. IIRC at that date no real standards
existed, BSW coming in around the mid 19th century in the UK, so I
expect the threads were produced to suit in the factory which certainly
seems to be supported by the other mish-mash of threads else where in
the items. In the end I single point cut the main suspension rod thread
at one end to suit the female piece it mated with and the non-visible
end I fitted with a M10 helicoil.

================================================== =============

When I hear stories like that, I always wish I could be there when the
next handyman tries to repair the custom thread. g
It might be amusing but I doubt it will happen in my lifetime. If they
know something about the history of threads and the date of the piece
then they might realise why the threads are oddball to modern eyes. The
one that got helicoiled was only visible when the piece was dismantled
and the wrought iron suspension rod had rusted in and had to be machined
out so the thread insert was a good option. The one where I kept the odd
thread had a good female thread in a brass casting and would have been
visible on close inspection but not seen in the normal way as it was in
the top suspension eye . As the female thread was good and the casting
somewhat asymmetric it was easier to cut the thread to the odd
specification. Many of the other threads at the ends of the arms which
coupled the candle holders and drip trays to the arms looked more like a
deep Edison screws thread rather than a normal V form.

I don't know much about old screw forming techniques but the oddball
thread was larger than the rod it was on, like it was rolled rather than
cut, but I didn't think they did that in the early 19th century. Any
thoughts.

BTW the reason for the repair was that the light had fallen from the
ceiling. It seems a water leak had allowed water to collect in the
hollow brass ball at the bottom of the light unknown to the owners and
about 6 years after the leak the central suspension rod had rusted to
the point it gave up and the brass 2 tiered 12 light assembly fell to
the floor bending and breaking many of the arms. The bulk of the repair
was the work to straighten and repair the breaks. This is a similar light
http://www.lassco.co.uk/?id=58&tx_ev...5Buid%5D=13747


My ancient plumbing contains a few brass parts that I've had to
custom-thread, but I don't think it will all last before I have to
replace the whole works. I've already succumbed to plastic pipe in
place of oakum and lead on my cast-iron waste pipes. so the end is near.

The spindle on one of my tub faucets is a piece I turned from the
bronze propeller shaft of a 50' commercial fishing boat, with the
splines cut by cranking the feed handle on my lathe, with a lathe bit
clamped in my milling attachment.

That's why my wife calls me a cheapskate.

No machinists here anymore?
 

On Oct 16, 11:14*pm, "Ed Huntress" wrote:


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


Ed Huntress

I did that because it did not seem pertinent to what I was replying
to. I was saying that 20 tpi seems to be the most prevalent thread.
Not that there are not other sizes, just that 20 tpi seems to be the
most common.

I looked at the specifications for door spindles at both Home Depot
and Lowes. You would think that they would include the TPI in the
specs, but they do not.


Dan

No machinists here anymore?
 

"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

No machinists here anymore?
 

"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?

No machinists here anymore?
 

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.

No machinists here anymore?
 

On 10/17/2011 08:34 AM, Jimmy Suarez wrote:
My next question is how do
you thread a square rod without breaking the die?

Thread the rod while it's round and then mill the sides flat?

--
Bob Nichols AT comcast.net I am "RNichols42"

No machinists here anymore?
 

Robert Nichols wrote:

On 10/17/2011 08:34 AM, Jimmy Suarez wrote:
? My next question is how do
? you thread a square rod without breaking the die?

Thread the rod while it's round and then mill the sides flat?


Thread it on a lathe, with shallow cuts.


--
You can't have a sense of humor, if you have no sense.