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#212989 - 03/05/14 12:39 PM Screws in EMT connectors
gfretwell Offline


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Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
I picked up some Halex steel EMT set screw connectors.
I decided I would see if I could find some stainless hex screws for them, thinking that is an easy thing. After 15 minutes at Ace Hardware we figured out these use a M5-1.0 thread which seems not to actually exist anywhere (web search came bank no joy too).
What was wrong with the good old 8-32/10-32 or even a M5-.80?

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Greg Fretwell
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#212990 - 03/05/14 12:50 PM Re: Screws in EMT connectors [Re: gfretwell]
HotLine1 Offline


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Registered: 04/03/02
Posts: 6778
Loc: Brick, NJ USA
Greg:
Did you try McMaster?? They have never let me down.
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#212991 - 03/05/14 12:56 PM Re: Screws in EMT connectors [Re: gfretwell]
HotLine1 Offline


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Registered: 04/03/02
Posts: 6778
Loc: Brick, NJ USA
Did you see this (from a real quick search)

"The 10-32 (10 gauge, 32 threads per inch) is very close to the M5x0.8 mm/thread. The 1/32-inch thread is 0.03125 inch per thread. Multiply by 2.54 cm/inch and you would get 0.794 mm per thread, which may be tolerably close to 0.8 mm of the metric screw. As already noted, the 10-gauge screws major diameter of 0.1891is going to be slightly smaller than 0.19685 of the 5 mm screw (by approximately 8 thousandths). Since a "tight fit" is in the range of 2 thousandths, you will have trouble torquing the wrong sized screw into a 5mm threaded hole or nut. "
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#212992 - 03/05/14 01:36 PM Re: Screws in EMT connectors [Re: gfretwell]
Tesla Offline
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Registered: 06/16/04
Posts: 1273
Loc: Sacramento, CA
Greg...

You'll have a quicker time reaming out the holes and re-tapping them to suit.

I am puzzled. If the bodies are common steel -- how can SS provide advantage?

&&&

American engineers use 'threads per inch' as a metric.

European engineers adopted 'millimeters per thread' as a metric.

This is why Hotline's math was necessary.

It's also why the ordinary Joe is stumped when looking at metric fasteners.

At first blush, it's not obvious which thread is coarse or fine.

M5x0.8mm is going to be 'finer' than M5x1.0mm.

Most of the metric threads on sale in America are destined for the automobile -- hence FINE threads.

In our trade, most of the threads are coarse:

10 x 24 versus 10 x 32
1/4 x 20 versus 1/4 x 28
5/16 x 18 versus 5/16 x 24
3/8 x 16 versus 3/8 x 24

So I'm not surprised that M5x1.0mm is scarce.
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#212993 - 03/05/14 02:48 PM Re: Screws in EMT connectors [Re: gfretwell]
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
The 10-32 screws rattle around in the hole. I think they would just strip out if you tried to get them tight.

I was actually surprised that I did not find them on a European or Asian web site tho.
These connectors are Hecho en India. Maybe it is an old BA size or something.

Tesla, the connector is galvanized and I am painting it but the screws are just common steel. They will rust in place and you will never get them out if you want to.

BTW this is not going to be a raceway, I am making a frame for a canopy awning. EMT just seemed to be a handy material that I had the tools to work with.

The screw in the center is the one I am going for.


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Greg Fretwell
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#212994 - 03/05/14 05:20 PM Re: Screws in EMT connectors [Re: gfretwell]
Tesla Offline
Member
Registered: 06/16/04
Posts: 1273
Loc: Sacramento, CA
It's actually possible to use Locktite as anti-seize compound. (don't use red)

Perhaps Locktite Green 290

Perhaps Locktite Blue 242

http://www.loctiteproducts.com/p/t_lkr_blue/overview/Loctite-Threadlocker-Blue-242.htm

" It protects threads from rust and corrosion and prevents loosening from shock and vibration."


A single tube should be enough for your entire project.

It's also to be recommended for set-screws in hole saws and such. (Green 290)

I'm not a paid spokesman, BTW.


Edited by Tesla (03/05/14 05:22 PM)
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Tesla
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#212995 - 03/05/14 07:58 PM Re: Screws in EMT connectors [Re: gfretwell]
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
I just went with the manufacturer's screws and a good coat of paint. I am going to hit it again now that it is up to get any dings. I guess if I need to take it apart I will use my grinder wink

In the end it is just $40 worth of pipe and a half dozen brazing rods.



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Greg Fretwell
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#212996 - 03/05/14 08:20 PM Re: Screws in EMT connectors [Re: gfretwell]
HotLine1 Offline


Member
Registered: 04/03/02
Posts: 6778
Loc: Brick, NJ USA
Nice job Greg!!
I'd put a smiley here, but I don't have them.
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John
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#212997 - 03/05/14 08:45 PM Re: Screws in EMT connectors [Re: gfretwell]
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
I am still confused by exactly what size screws these are. They appear to be M5-1.0 but that does not seem to exist. It is not an SAE thread so that leaves me thinking it is something they use in India that nobody else knows about.

I guess it is time to ask Halex tech support.
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Greg Fretwell
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#212998 - 03/05/14 09:22 PM Re: Screws in EMT connectors [Re: gfretwell]
Tesla Offline
Member
Registered: 06/16/04
Posts: 1273
Loc: Sacramento, CA
ISO / Metric ==> M5 means metric 5 millimeter.

ISO 261:

ISO 262:

0.5 is deemed FINE

0.8 is deemed COARSE

As you might imagine, the global manufacturing trend has caused even American manufactures to shift over to metric.

The pitch of 1.0 mm in an M5 fastener is a non-standard type.

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Tesla
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