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#195413 - 08/01/10 10:23 AM Threading aluminum pipe.
Merlin Offline
Member

Registered: 01/27/04
Posts: 170
Loc: NW Indiana
Ok...so I need some help. Although I am not new to the industry, I have never tried to cut threads in aluminum pipe. I am wiring a new grain bin and using aluminum pipe. It is great to work with.....well it was until I had to cut and thread it.

Can anyone one give me any pointers on how to thread this stuff? What do I need to use for a threading compound? I can cut the threads ok but when I go to back off the die, the cuttings get bound up in the threads and destroy what I just cut. Help....please!

Thanks, Merlin

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#195414 - 08/01/10 01:24 PM Re: Threading aluminum pipe. [Re: Merlin]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
Sure .... prepare to forget everything you think you know about pipe!

First off, aluminum is considerably softer, weaker, and -paradoxically - a lot less forgiving than steel. You'll have to take considerable care not to crush or fltten it in your vise, when bending it ... and you can forget about 'unbending' it if you make a goof.

Wear gloves - the oils in your hands will oxidize the aluminum, and turn your skin black.

As for cutting threads, go to a machine shop supply house, or visit one online, like MSC Direct. You'll want to use a water-based cutting fluid - I reccomend LPS Green - rather than the usual threading oils.

Once you thread something tight in aluminum, you can forget about loosening it; you'll usually destroy the threads. It's probably a real good idea to use Noalox on the fittings for this reason.

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#195415 - 08/01/10 01:48 PM Re: Threading aluminum pipe. [Re: renosteinke]
Merlin Offline
Member

Registered: 01/27/04
Posts: 170
Loc: NW Indiana
Thanks, Reno. So can I use regular pipe threading dies or do I need special dies?

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#195416 - 08/01/10 04:07 PM Re: Threading aluminum pipe. [Re: Merlin]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
Regular dies are just fine .... just pay attention to the chips, and back the dies off several times to break the chips. Be wary of the chips as well, as they will iterally be razor sharp.

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#195418 - 08/01/10 07:18 PM Re: Threading aluminum pipe. [Re: renosteinke]
Merlin Offline
Member

Registered: 01/27/04
Posts: 170
Loc: NW Indiana
Thanks for your help. I tried a different set of dies and they worked much better. I must of had a dull die that was causing me some aggravation. I actually used WD-40 for lube and it worked great. Thanks again for the info.

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#195428 - 08/02/10 03:09 PM Re: Threading aluminum pipe. [Re: Merlin]
Alan Belson Offline
Member

Registered: 03/23/05
Posts: 1801
Loc: Mayenne N. France
The problem with cutting near pure aluminum is that it's so soft. You need an acute rake angle on cutting tools to get them to penetrate properly, and a standard die set will usually be set up for steel. That usually means they cut oversize first pass. Reno's answer of a cutting 'gunk' plus cycling the die down is the solution. Aluminum also tends to 'gall' or weld itself to cutting edges, so it's advisable to check and clean any galls off regularly.
_________________________
Wood work but can't!

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#195431 - 08/02/10 06:37 PM Re: Threading aluminum pipe. [Re: Alan Belson]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6785
Loc: Brick, NJ USA
Got to go with Reno. The new set of dies will be a big help too.
_________________________
John

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#195439 - 08/03/10 02:21 AM Re: Threading aluminum pipe. [Re: HotLine1]
Alan Belson Offline
Member

Registered: 03/23/05
Posts: 1801
Loc: Mayenne N. France
I seem to remember that the manual pipe threader in our fitting shop withdrew the 4[?] dies once you got to depth, so you did not have to unscrew the pipe to get it out.
_________________________
Wood work but can't!

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#195444 - 08/03/10 10:34 AM Re: Threading aluminum pipe. [Re: Alan Belson]
frenchelectrican Offline

Member

Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
Alan.,

Yes I did recall in the Ridge companie they did have one like that and it have special cam on it when you get done threading the alum pipe then hit the lever which it will pull the dies out then you can slide it out but becarefull it don't take much to nick it.

But as other mention a new die and diffrent cutting fluid will work just fine.

Merci.
Marc
_________________________
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


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#195446 - 08/03/10 11:12 AM Re: Threading aluminum pipe. [Re: frenchelectrican]
Alan Belson Offline
Member

Registered: 03/23/05
Posts: 1801
Loc: Mayenne N. France
You won't believe this, but we used lard!
_________________________
Wood work but can't!

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