Talk:Nominal Pipe Size

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Contents 1 Thank you contributors! 2 Lamp pipe (nipple) threads: 1/8-IP, 1/4-IP 3 What is the thread called on a (U.S.) standard shower riser with OD of 5/8" (.625)

[edit] Thank you contributors!

I am really surprised to see this entry. Good work. Excellent effort.

THIS IS VERY HELPFULLYItalicTHANKS FOR YOU SUPPORT text'

Very Useful information. I had been looking for this information for months. Now that I have this info, life becomes so much easier.. Very good work, thank you... Kindly arrange the table converter from NPS to DN —Preceding unsigned comment added by 122.161.30.137 (talk) 07:27, 9 November 2007 (UTC)

[edit] Lamp pipe (nipple) threads: 1/8-IP, 1/4-IP

Lamps and light fixtures here in the U.S. use standard pipe nipples of size "1/8-IP". I googled "1/8-IP" and found that these are nicely explained at [1], which says that they come from a 19th-century standard for wrought iron pipe by a company called Briggs. Their cited source is "Standard Pipe and Pipe Threads." Transactions of the American Society of Mechanical Engineers, volume 8, Page 29. I suspect that maybe this IP standard evolved into NPS, but I do not know that as fact. It would be great if someone who works in engineering related to pipe could work this info into this article or whichever other article would be logical. I won't have time to read and research into this, but maybe someone who is already well versed in this field can contribute the info to Wikipedia without too much time expenditure. — ¾-10 16:37, 21 November 2007 (UTC)

Well, the article already mentions iron pipe size, which seems to be what you're talking about.--Yannick (talk) 01:27, 22 November 2007 (UTC)

Ah, OK, upon rereading iron pipe size, I find that it is probably referring to one and the same thing. Thanks. One thing I don't get. According to American Machinists' Handbook, 2nd ed, pp 42-43, the Briggs threads are actually taper threads, for sealed joints; but yet they are used in lamps and light fixtures today as a non-taper thread. (You can buy nipples in any length, from ½" to 12", with all threads perfect, i.e., full and not tapering). I guess there is nothing to "get"—it is what it is—but I am surprised that they effectively took a taper thread standard and morphed it into what is essentially a machine screw thread standard. And the major diameter is .375, rather than .405. Essentially it is a little ⅜-27 machine screw thread, standard to nothing but lamps and light fixtures. I wanted to just buy some cap screws with this thread, but now I see why my light fixture was made stupidly to begin with: you can't buy them. It looks like I may have to make them the ole-fashioned way, with the quick-change gear-box set to 27 and a blank turned to .375. I didn't expect to have to do this simple job from scratch. I am a little miffed that we are still bound to this size in 2007. I vote for abolishing it tomorrow. To hell with maintaining backwards compatibility with any legacy light fixtures; let the antiquarians turn custom threads when they need them—I want mine in a box from McMaster-Carr! Oh well, it is late and I will stop ranting! — ¾-10 03:07, 22 November 2007 (UTC)

Hmmm. There's a straight (non-tapered) version of the NPT called NPSM that's used for hoses and mechanical joints. But that .375 diameter doesn't sound right. I agree with abolishing legacy threads; let's just settle on M10 for light fixtures... (I'm well aware that would not be popular in the Western hemisphere.)--Yannick (talk) 04:41, 22 November 2007 (UTC)

[edit] What is the thread called on a (U.S.) standard shower riser with OD of 5/8" (.625)

This is the pipe that your shower head screws onto. The OD is 5/8" (.625). What is the name of this thread? I can't figure out this pipe size and pipe thread standard BS. Any help out there? — ¾-10 18:48, 12 January 2008 (UTC)