[de-nagorg]

Should not the I.D of black pipe be the size that it is sold as?

Example, I recently bought a 24" X 1/2" nipple to use as a repair of another item.

Using it as a limiter rod on an inversion table, but need to insert Bushings to adapt the nipple to be adjustable in length , to be movable to a steeper angle of inversion.

I bought 1/2" O.D. bushings, and they are sloppy fit, so I measured the I.D of the nipple, and it is 5/8".

Is this just poor manufacturing, or are the nominal sizes actually different
From the actual size?


ED

 

[joed]

According to this chart sched 40 1/2" pipe has internal diameter of .62. That is about 5/8.

https://www.metals4uonline.com/PipeSchedule10,40,80Specifications

 

[SeniorSitizen]

Pipe sizing has an interesting history and the reasons it is so screwed up, literally.


EDIT: EDIT:

 

[de-nagorg]

According to this chart sched 40 1/2" pipe has internal diameter of .62. That is about 5/8.

https://www.metals4uonline.com/PipeSchedule10,40,80Specifications

Thanks, 5/8 is 0.625 to be exact. :devil3:

So it is not as precise as machinist work after all.

ED


I found the correct bushings on e-bay, and ordered them for $2 each.

 

[dj3]

Different pipes have different I.Ds because they vary in width.
In your case, I assume for natural gas line, black iron fittings are made to be used ONLY with black iron pipes and/or plastic gas lines.

 

[bfrabel]

Yeah, with most kinds of pipe, the dimension that's listed is an approximate size. The outside of the pipe is really what's important so that the pipes can be connected together, but we don't order the pipe by that dimension.

Pipes can come in different "schedules" or thicknesses. Your 1/2" nipple could come in schedule 10, schedule 40, or schedule 80. Schedule 10 is paper thin, schedule 80 is super thick and heavy, schedule 40 is somewhere inbetween. All of these different schedules will have the same outside diameter so that they could all be threaded into the same fittings if you needed them to.

 

[joed]

The outside diameter of any size of pipe is constant. However if you want heavier gauge pipe the inside diameter will be smaller. If you look at the chart you will see the inside diameter of sched 80 is close to 1/2".