Would it be possible to tap threads into a piece of 1/8" thick sheet metal? For what it's worth, the threads I need to tap are 1/4-18 NPT. So if I'm doing my math correctly, that's .125 times 18, which means there will be 2.25 threads. Is that enough for it to catch?
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Tapping Threads into 1/8" Sheet Metal
- Thread starter mike7
- Start date
Fordman7795
Well-known member
If you are able to cut the threads it will be very weak. I doubt you will be happy with the results. Could you double up the thickness where you are tapping?
JJThrasher
Well-known member
Can you tap the threads? Probably. Willn it be strong? Not really. The question is, why? What are you attempting to do with these threads?
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Sent from my SCH-I535 using Tapatalk 2
Depends on what kind of stress you will putting on it , how many holes and if it is going to be on a movable item. I've done many such projects on Coal Mining Power centers and have done well but they on a stationary object. If you are able to use the pop rivet style nut that leaves a not on the backside you wont have ANY worries.
AmericanPreferred
Well-known member
- Joined
- May 8, 2013
- Messages
- 159
Self tapping sheetmetal screws may hold better, if through bolting with a nut is not an option.
Would it be possible to tap threads into a piece of 1/8" thick sheet metal? For what it's worth, the threads I need to tap are 1/4-18 NPT. So if I'm doing my math correctly, that's .125 times 18, which means there will be 2.25 threads. Is that enough for it to catch?
For a NPT thread you might get away with it if there are no loads on the thread other than the pressure. For pipe threads you might consider installing a bulkhead fitting.
lg
no neat sig line
rsanter
Well-known member
Drill a smaller hole
Use a punch to form a bit of a funnel in the metal. You will need tp support the back as ypu punch form the funnel shape.
This will give you more material to tap
Bob
Use a punch to form a bit of a funnel in the metal. You will need tp support the back as ypu punch form the funnel shape.
This will give you more material to tap
Bob
ilovevocs
Well-known member
How about a rivnut?
sparky5982
Well-known member
- Joined
- Feb 17, 2013
- Messages
- 89
Why not spot weld a nut to the sheet metal? I see this commonly done on thin metal paneling, such as for machine panels.
theoldwizard1
Well-known member
A lot of it depends on how much load is going to be placed on it !
Excellent idea !
For support you could use a block of wood with a hole drilled in it a bit bigger than the pipe. 1/4" pipe has an OD of 0.540, so maybe a 5/8" (0.625") spade bit for the wood block.
Drill a smaller hole
Use a punch to form a bit of a funnel in the metal. You will need to support the back as you punch form the funnel shape.
This will give you more material to tap
Bob
Excellent idea !
For support you could use a block of wood with a hole drilled in it a bit bigger than the pipe. 1/4" pipe has an OD of 0.540, so maybe a 5/8" (0.625") spade bit for the wood block.
For a NPT thread you might get away with it if there are no loads on the thread other than the pressure. For pipe threads you might consider installing a bulkhead fitting.
lg
no neat sig line
That's the way I would do it.
Is the fitting going to be either holding pressure or under liquid? If either of those are the case, it won't work. If there's going to be any stress on the pipe, it won't work. If it's just a place to dump in fluid, maybe. If you don't have a bulkhead fitting handy (and who does?), you can cut the threaded end off a ****** and weld that on. Don't try to weld a regular pipe fitting on, though, as they're almost always cast.
Also, never try to weld on anything that's going to be holding above atmospheric pressure. The weld needs to be perfect, and the steel needs to be properly tempered or you'll have a brittle area that can fail with very bad results.
Also, never try to weld on anything that's going to be holding above atmospheric pressure. The weld needs to be perfect, and the steel needs to be properly tempered or you'll have a brittle area that can fail with very bad results.
Scrambler82
Active member
What purpose will this thread serve ?
What are you actually doing ?
Luck
What are you actually doing ?
Luck
senlow
Well-known member
Drill a smaller hole
Use a punch to form a bit of a funnel in the metal. You will need to support the back as you punch form the funnel shape.
This will give you more material to tap
Bob
This is a good method. I've done this many times.
HAP
Well-known member
Look into "Flow Drill"
R,
HAP
HAP
Jagmandave
Well-known member
Wow Hap, that's pretty cool tech, wonder how expensive the bits are?
Bruce Lancaster
Well-known member
- Joined
- Apr 3, 2006
- Messages
- 1,642
Rsanter has it. From the bits of information given, sounds like a small brass fitting going into a tank or something...
So use that method, clean and tin the sheet (this can be largely taken care of before making the hole!) and tin the fitting. Screw'em together, heat'em up with a propane torch, and flow on a bit more solder. Should be good enough for anything short of the space shuttle. Actually, fine for that too, now that the thing doesn't move around.
So use that method, clean and tin the sheet (this can be largely taken care of before making the hole!) and tin the fitting. Screw'em together, heat'em up with a propane torch, and flow on a bit more solder. Should be good enough for anything short of the space shuttle. Actually, fine for that too, now that the thing doesn't move around.
HAP
Well-known member
Wow Hap, that's pretty cool tech, wonder how expensive the bits are?
They are around $300.00 in the US. I bought one direct from China for $50.00.
It works just as shown...
R,
HAP