Anyone know where to find a 1/8-28 NPT tap?

Reply

  #1  
Old 06-02-03, 09:14 PM
MikeVB
Visiting Guest
Posts: n/a
Anyone know where to find a 1/8-28 NPT tap?

I have a compressor with a 1/8-28 NPT fitting and I need to find a way to convert it to fit into a standard fitting such as a 1/8-27 NPT or a 1/4" NPT. Any idea who sells one of these?

Thanks

Mike
 
Sponsored Links
  #2  
Old 06-03-03, 05:13 AM
mattison's Avatar
Member
Join Date: Mar 2003
Location: Cinti, OH
Posts: 5,549
Received 0 Votes on 0 Posts
Have you tried www.grainger.com ?
 
  #3  
Old 06-03-03, 06:13 AM
MikeVB
Visiting Guest
Posts: n/a
Originally posted by mattison
Have you tried www.grainger.com ?
Yes I have and they don't have one.

Mike
 
  #4  
Old 06-03-03, 10:48 AM
mattison's Avatar
Member
Join Date: Mar 2003
Location: Cinti, OH
Posts: 5,549
Received 0 Votes on 0 Posts
You may want to post this in the tool section. Those guys can find anything I'll bet.
 
  #5  
Old 06-03-03, 01:24 PM
Member
Join Date: Jul 2001
Location: Maine
Posts: 299
Received 0 Votes on 0 Posts
1/8-28??? How did you determine that it was that particular thread size? I have never heard of it myself. I would think that 1/8-27 would engage o.k. anyway because you wouldn't normally have a full inch of engagement. Over an inch your only talking about an extra thread.

If it is an issue, pickup a 1/8-27 tap and chase the thread, just to be sure and add a little teflon paste to the tape.
 
  #6  
Old 06-03-03, 02:15 PM
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 6,862
Received 96 Votes on 88 Posts
Where was the compressor made. Could it be metric. There is such a thing as 1/8 - 28. It is listed on my chart under the British & ISO pipe sizes.
 
  #7  
Old 06-03-03, 03:37 PM
Member
Join Date: Jun 2002
Location: Brethren, Mi
Posts: 1,648
Received 0 Votes on 0 Posts
Walk right into a major auto parts store such as a NAPA. They carry almost all available taps.
 
  #8  
Old 06-03-03, 06:01 PM
MikeVB
Visiting Guest
Posts: n/a
Originally posted by toni1595
1/8-28??? How did you determine that it was that particular thread size? I have never heard of it myself. I would think that 1/8-27 would engage o.k.
I determined it was 1/8-28 NPT because it is the same diameter roughly as a 1/8-27 NPT fitting but a thread pitch gauge shows it as 28 TPI perfectly. A 1/8-27 fitting engages the fitting but only for about a half turn or so.

Mike
 

Last edited by MikeVB; 06-03-03 at 06:18 PM.
  #9  
Old 06-03-03, 06:05 PM
MikeVB
Visiting Guest
Posts: n/a
Originally posted by joed
Where was the compressor made. Could it be metric. There is such a thing as 1/8 - 28. It is listed on my chart under the British & ISO pipe sizes.
Joed,

This compressor was made in Denmark and according to their web site the hose coming out of the compressor that I am talking about is 1/8 and not metric. Their web site does not say the thread pitch though.

I thought it might be a 1/8-28 BSP as you stated, but the British 1/8-28 has a 55 degree thread pitch instead of the 60 degree we use. If it was 55 degrees it would look funny with a 60 degree thread pitch gauge on the threads. The 28 TPI gauge fits on it perfectly and the angle of the threads and the gauge look like a match which would make it 60 degrees. I am taking a fitting to work tomorrow to have the machinist look at it.

Mike
 
  #10  
Old 06-03-03, 06:16 PM
MikeVB
Visiting Guest
Posts: n/a
Originally posted by mattison
You may want to post this in the tool section. Those guys can find anything I'll bet.
Thanks Mattison.

I forgot this was the electrical forum. lol

I saved it in my bookmarks but failed to go to the starting page URL to save it.

Thanks again

Mike
 
  #11  
Old 06-03-03, 06:25 PM
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 6,862
Received 96 Votes on 88 Posts
Are you sure it is not metric. My thread guages 0.9mm matches 28tpi.
 
  #12  
Old 06-03-03, 06:36 PM
MikeVB
Visiting Guest
Posts: n/a
Originally posted by joed
Are you sure it is not metric. My thread guages 0.9mm matches 28tpi.
Joed,

I noticed that last night myself. I am not positive that it is a SAE size and not metric. I am going to call the manufacturer tomorrow and see if I can find out.

Thanks

Mike
 
  #13  
Old 06-03-03, 06:59 PM
Member
Join Date: Jul 2001
Location: Maine
Posts: 299
Received 0 Votes on 0 Posts
Yes, there is a 1/8-28 thread. I had to look it up for myself. It is a B.S.P. thread. I had never ran across it in my years of dealing with the threading industry. I guess you can learn something everyday.

But, in reality, I feel that in this case you could chase out this thread with a 1/8-27 tap and would not have a problem. Especially where you are only talking about a pitch difference of .0013".

You may be able to get a machine shop to turn you one out for a small fee, if they have the die available. I am a little surprised that the vendor don't have an adapter available to convert the thread to N.P.T. anyway....... Good for business and all!!
 
  #14  
Old 06-03-03, 08:25 PM
MGJ
Visiting Guest
Posts: n/a
thread question

I work with both NPT and BSP standards daily(machinist).If I were you I'd run a 1/4-27 tap into hole then teflon tape(two wraps) fitting.Put grease on tap to catch metal chips.
 
  #15  
Old 06-03-03, 10:03 PM
MikeVB
Visiting Guest
Posts: n/a
Re: thread question

Originally posted by MGJ
I work with both NPT and BSP standards daily(machinist).If I were you I'd run a 1/4-27 tap into hole then teflon tape(two wraps) fitting.Put grease on tap to catch metal chips.
1/4-27? 1/4 NPT threads are 18 TPI last time I looked. I thought you were a machinist? Just kidding with you MGJ. I know you meant to say 1/8-27 my friend.

Thanks for the tips. I have a fitting here that I believe is stainless and it has a male fitting and two female threaded openings on it. I think I will put one female fitting on the compressor, tap the other female fitting to 1/8-27 NPT and plug it and use a die on the male end to make it 1/8-27 also to fit whatever fitting I need to convert it from a 1/8 to the size of the braided hose I buy.

Do you see any problems with tapping stainless over brass? Will it still work alright going over the existing threads?

Thanks

Mike
 
  #16  
Old 06-03-03, 11:36 PM
Member
Join Date: Jun 2002
Location: Brethren, Mi
Posts: 1,648
Received 0 Votes on 0 Posts
if you never care about getting it apart again locktite works great for mismatched stuff.
 
  #17  
Old 06-04-03, 06:11 PM
MikeVB
Visiting Guest
Posts: n/a
Re: thread question

Originally posted by MGJ
I work with both NPT and BSP standards daily(machinist).If I were you I'd run a 1/4-27 tap into hole then teflon tape(two wraps) fitting.Put grease on tap to catch metal chips.
MGJ,

I took the fitting to work today and had our machinist look at it.
He said it is metric and is not pipe threads. He said it is a 9.5 x .9 M according to the measurements.

Mike
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: