27 tpi

O

oldbrock

Hot Rolled

Joined

Feb 22, 2008

Location

Glade BC, Canada

• Apr 7, 2008

• #1

Had to screwcut a 1/8" pipe thread yesterday. Guess what? qcgb had 26 and 28 . the pitch is.03703" the closest feed on my 10K is A 2 which is .0379. So to hell with it, locked in the feed and taper attachment and forward reversed it. It actually fit, good job it is a short thread. Any better ideas out in South Bend land? Peter

 

J

jkull

Aluminum

Joined

Apr 24, 2004

Location

Illinois

• Apr 7, 2008

• #2

SB Info for 27 TPI

Here is a scan of the South Bend literature showing the setup for 27 TPI.
--- Jim

 

Attachments

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  27 TPI001.jpg

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enginebuilder

Stainless

Joined

Dec 1, 2005

Location

Kalispell, Montana

• Apr 8, 2008

• #3

I had my first run in with 27 TPI today, on a light fixture of course. Anybody make taps for this bastard pitch?

Jim

 

Jim B.

Hot Rolled

Joined

Nov 8, 2004

Location

Northern NJ

• Apr 8, 2008

• #4

The 27 TPI thread is actually a 'standard' thread. Its either 1/16 or 1/8 pipe. Pipe is normally tapered, however these two also come in straight versions.
Enco has them in their catalog.

Jim B.

 

G

garyphansen

Titanium

Joined

Feb 9, 2004

Location

Traverse City, MI

• Apr 8, 2008

• #5

The heavy 10 exteneded range gear box has a 27tpi setting. (might be its only real advantage) Gary P. Hansen

 

David C.

Aluminum

Joined

Jun 10, 2007

Location

Fort Washington, PA

• Apr 8, 2008

• #6

You could just use a tap or die.

Thanks,
David

 

aametalmaster

Diamond

Joined

Jan 11, 2005

Location

Salem, Ohio

• Apr 9, 2008

• #7

enginebuilder said:

I had my first run in with 27 TPI today, on a light fixture of course. Anybody make taps for this bastard pitch?

Jim

Click to expand...

Jim, I don't know what you do to lamps but this is the place i use for my old parts...Bob http://www.antiquelampsupply.com/category/205-3/

 

O

oldbrock

Hot Rolled

Joined

Feb 22, 2008

Location

Glade BC, Canada

• Apr 9, 2008

• #8

27tpi

David C, I was making a collet for a die grinder extension and it needed to be perfectly concentric as it turns at 30,000 rpm so wouldn't trust a die even if I had one. I always screwcut in preference to using a die unless I'm just cleaning up a damaged thread. Thanks for the chart JKULL but I couldn't read it, Tried to transfer and enlarge it but no numbers or words came through just blobs.This is the die grinder extension I was working on. Peter

 

O

oldbrock

Hot Rolled

Joined

Feb 22, 2008

Location

Glade BC, Canada

• Apr 9, 2008

• #9

27tpi

Thanks to you all for your input, I found the chart buried in my files with the chart. I have to make a 42 tooth gear, no sweat. Peter

 

J

jkull

Aluminum

Joined

Apr 24, 2004

Location

Illinois

• Apr 9, 2008

• #10

The forum doesn't allow high resolution scans. If you send me an email I'll send the high resolution version as well as the other side of the sheet which has more information. -- Jim

 

S

sinned

Aluminum

Joined

Feb 9, 2004

Location

Norte IllinoiSe

• Apr 9, 2008

• #11

attachements are limited in size.

put the picture up at a hosting site and link it back here.

search "posting pictures" and you will get plenty of reading.

 

1yesca

Stainless

Joined

Jun 1, 2004

• Apr 9, 2008

• #12

if you want to make a top punch for your star lub sizer on your south bend then you will be cutting a 27 tpi as it is 1/2" x 27 tpi

 

Paula

Titanium

Joined

Sep 16, 2005

Location

Indiana, USA

• Apr 9, 2008

• #13

Here are the pages I think Jim wanted to post (click on either for a larger view):



Paula

 

O

oldbrock

Hot Rolled

Joined

Feb 22, 2008

Location

Glade BC, Canada

• Apr 9, 2008

• #14

27tpi

thanks guys and dolls. Got er done now. Peter

 

T

Tex-VA

Cast Iron

Joined

Jan 16, 2008

Location

Northern VA - USA

• Apr 10, 2008

• #15

I don't want to pile on here but I have some more information that might be helpful. I was in need of 27 tpi for microphones and mic stands so I made a 42 tooth gear. It was cut on my little cnc'ed micro mill. I made a gear at a CAMS ( http://www.cams-club.org/ ) meeting a while back to show of the mill. I can't find a photo of the gear on the lathe but I did find the below shots of the hand-out from the meeting and photo of the gear cutting. If there is any way I can help you please let me know. Tex

 

lwbates

Cast Iron

Joined

Sep 24, 2007

Location

Westport Oregon

• Apr 11, 2008

• #16

Threads the qc aint got

Just to keep the thread going, it is possible to adjust thread pitch, if you are machining between centers. By offsetting the tailstock to the same inch per foot as the taper attatchment is set to, you effectivly increase the TPI by an amount that is determined by the amount of offset of the taper attatchment and tailstock. Theoretically you could cut a tapered thread like NPT, by setting the tapers different from each other by a certain amount. The amount for pipe thread? What do I look like, a math whiz? I'm dizzy just from writing this!
lwbates