Black steel pipe available with male and female threads?


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Old 02-06-16, 04:49 AM
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Black steel pipe available with male and female threads?

I'd like to replicate a project my Dad made years ago. It involves joining lengths of pipe by threading them together. The black steel plumbing pipe at Home Deep has male threads on both ends, and you can get joins with female threads. The joins have a larger outside OD than the pipe, though, and for my application I'd like to keep the profile as narrow as possible.

Does that black steel pipe come with both male and female threads, so i could daisy chain them together and maintain a consistent profile?

Thanks!
 
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Old 02-06-16, 05:00 AM
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Short answer from a non-plumbing pro: No. Physically the pipe needs to be larger in order to have female threads.

Are you sure he used black pipe and not something like electrical PVC conduit. Electrical PVC has bell ends to join the conduit together without couplings. This keeps the pipe fairly consistent in size.
 
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Old 02-06-16, 05:01 AM
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It sounds like the original pipes in your Dad's day with male & female joins and a narrow profile was better than what is available today being both male ends requiring female connectors and wider. Ask Home Depot why the change for the worse other than them trying to make more money by selling more parts (the female connectors).
 
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Old 02-06-16, 05:22 AM
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Thanks for replies- should have explained, it's not a plumbing project. I want to run wiring under the driveway (and starting with a sidewalk to get past the learning curve). My Dad closed off the end of one pipe and ground it into a bullet shape. He dug holes on both sides of the driveway, threaded a section of pipe onto the bullet, and sledgehammerred the pipe through the dirt under the drive. When the pipe was all the way in he threaded on another length and repeated until the bullet appeared on the other side.

Unfortunately my Dad is no longer with us, or else i'd ask, but my *memory* is that he did not use female connectors. He worked at a place that could have ginned up pipe with male and female threads on a one-off basis, maybe that was it. I've started a practice bullet but haven't yet welded it, just trying to think ahead to the next step.
 
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Old 02-06-16, 05:44 AM
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Bullet

How do you guide the bullet to make it come out on the other side at the desired location?

The short sections with female threads are called couplings.
 
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Old 02-06-16, 05:50 AM
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You should not use black pipe for electrical anyway.

There are many ways to boar under sidewalks using a similar method your dad used. The pipe/sledge hammer method works well, but I have just used open pipe. The end will just full up with dirt. Another method is a water jet which also works well, but is very messy!

Go on google and search "digging under sidewalk" and you will see many methods.

I would suspect your dad took a pipe cap, and shaped it into a point, then welded it on.

make sure to use either UF cable or PVC conduit for your wiring.
 
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Old 02-06-16, 01:29 PM
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I recall my Dad was very careful to keep the pipe level and straight while hammering. That kept the bullet from drifting off course, and the pipe showed up in the spot as expected, visible in the hole dug on the other side of the driveway.

Why is black steel not used as conduit, and galvanized steel is ok? (Not challenging your statement, i'd like to know!) Is it because this is an outdoor application vs. indoor, and does it matter that i plan to use DC landscape lights?

Thanks
 
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Old 02-06-16, 04:21 PM
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You want the pipe to be protected from the water and earth. Galvanized will last much longer.

If you are only running low voltage wiring thru it then you can use anything you want as it's only a mechanical sleeve.

Normally when we burrow under a sidewalk we use a larger than needed piece of galvanized pipe and use it only as a sleeve by running a small, usually PVC, pipe thru it.

It can be a crap shoot going under a sidewalk. If you hit a rock.... the pipe will drift.
 
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Old 02-07-16, 04:58 AM
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At Tolyn's suggestion above i googled it, and found a commercial product called Bullet Mole, which is essentially what my Dad built years ago. Bullet mole uses solid round bar instead of pipe; in their videos they pull the bar stock out and replace it with pvc conduit. That system uses connectors with OD greater than the bar stock, which answers one of my questions. That Bullet Mole setup is VERY similar to my Dad's.


Cool, i think i'm good to go. i have a design change in mind, now.
 
 

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