EEVblog Electronics Community Forum
Electronics => Mechanical & Automation Engineering => Topic started by: Alex Eisenhut on July 31, 2021, 04:52:57 pm
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I would like 10 steel (exact alloy not important, it's for a desk) of about 50mm X 10mm X 2mm thick with two M6x1mm right hand tapped holes in them.
Do you think China is the way to go or should I look into local Montreal places?
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I would like 10 steel (exact alloy not important, it's for a desk) of about 50mm X 10mm X 2mm thick with two M6x1mm right hand tapped holes in them.
Do you think China is the way to go or should I look into local Montreal places?
At x10 quantities this is a small job for a hobbyist, you just have to find them. Like on Craigslist maybe?
You start with a 10mm x 2mm steel bar: https://hardware-warehouse.co.uk/drawn-steel-flat-bar-10mm-2mm-1m
You cut off 50mm chunks, then mark where you want your holes. Drill and tap with a drill press, deburr and file as needed.
Tools: Cutoff saw, drill press w/ vise, tap set, deburring tool, file. If you were extraordinarily concerned about a particular dimension, perhaps the spacing between the holes, you could do that part in a small, simple CNC machine. If you have a local makerspace, they may have all of these tools readily available. Mine does.
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Random thoughts.... Ignore if I am wrong
Quote: "2mm thick with two M6x1mm right hand tapped holes in them"
Maybe the image in my head is different to what you are asking, but.....
1) .... Tapping a 1mm deep hole into 2mm thick steel seems like a very difficult thing to do.
EDIT: ignore me - I am being really dumb! - of course you mean 1mm pitch, not 1mm depth. doh :-[
2) How will you prevent the steel from going rusty?
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I think “1mm” is the pitch of the 6mm diameter thread, not the depth.
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Yeh.... spotted that right after posting - edit was 8 seconds too slow
Apart from the rust issue, this looks like a simple hobby project
Wonder if Aluminium would be good enough?
Softer and easier to strip the threads - but no rust issues.
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Have you tried Cut2SizeMetals in Indiana? They do stainless steel. I have used them for small quantities of aluminum cut to my dimensions.
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Thanks, as I was rearranging my computer desk I sort of found that its previous owner over-tightened the bolts. It is an IKEA Jerker desk and as seems to be typical with IKEA stuff there's always some weak point. The metal plates are what hold the shelves to the risers. The screws have metal bits stuck in the threads and the metal plates have worn out tapped holes. Everything's wiggly now.
I could weld some metric bolts to the plates but I can't do that either. I live in a small apartment and any metal work is not a great idea in here...
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If it is really a question of just stripped threads, there are now various brands of thread repair kits. Helicoil was one of the earliest, but a search on thread repair will be more productive. A rivet version is made for thin metal. They are really quite good. In fact, some engines come with them standard for the spark plugs. The rivet version is also used OEM.
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Forgot to include the website: https://www.cut2sizemetals.com/ (https://www.cut2sizemetals.com/)
If tapping or welding is too difficult, there are self-clinching nuts (e.g. "Pemnuts" https://www.pemnet.com/fastening-products/pem-self-clinching-fasteners-new/ (https://www.pemnet.com/fastening-products/pem-self-clinching-fasteners-new/) ) that can be merely hammered into a hole in metal plate.
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Riv-nuts might work, as would simply gluing nuts to the plate with epoxy--the tension when tightened will hold without depending on the glue. If there is space, these would be the easiest.
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I know that McMaster-Carr may be unavailable in Canada, but here is their page for metric pem-type nuts. https://www.mcmaster.com/pem/metric-stainless-steel-press-fit-nuts-for-sheet-metal/ (https://www.mcmaster.com/pem/metric-stainless-steel-press-fit-nuts-for-sheet-metal/)
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I would like 10 steel (exact alloy not important, it's for a desk) of about 50mm X 10mm X 2mm thick with two M6x1mm right hand tapped holes in them.
Do you think China is the way to go or should I look into local Montreal places?
Thanks, as I was rearranging my computer desk I sort of found that its previous owner over-tightened the bolts. It is an IKEA Jerker desk and as seems to be typical with IKEA stuff there's always some weak point. The metal plates are what hold the shelves to the risers. The screws have metal bits stuck in the threads and the metal plates have worn out tapped holes. Everything's wiggly now.
I could weld some metric bolts to the plates but I can't do that either. I live in a small apartment and any metal work is not a great idea in here...
Its doomed to failure. 2mm just isn't thick enough for a M6 thread to hold any significant load in mild steel. See https://genfast.com/wp-content/uploads/2016/09/Minimum-Thread-Engagement-Bolt-Failure-Chart-Metric.pdf
If you've got clearance for nuts, take the existing plates + enough nuts for a few spares + a box of *good* donuts, to a welder (maybe at an independent auto repair shop) and offer to pay time + materials. N.B. expect to have to re-tap the nuts after welding as they *will* distort slightly.
Otherwise you'll need the thickest plates you can fit (up to 6mm), and if the thickness is much under 4mm they'll probably need to be hardened after drilling and tapping, which any machine shop will probably quote you more than the desk to make!
Tim's suggestion would work *IF* you can stake them in place adequately which you don't have the tooling to do. Otherwise they'll be a PITA to fit tightly enough with hand tools and if they aren't an absolutely tight interference fit in their hole all the way around any cyclic sheer loading will wallow out the hole till they come loose.
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I've had reasonable luck using a bench vise to seat them in aluminum. A good c-clamp might work. Anyway, the screw will tend to hold the nut in place, so long as the hole is the right diameter.
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Would something like this work?
https://www.ebay.ca/itm/164212262751?epid=5038966732&hash=item263bd0475f:g:zAkAAOSwXbhexkwf (https://www.ebay.ca/itm/164212262751?epid=5038966732&hash=item263bd0475f:g:zAkAAOSwXbhexkwf)
An extra lazy solution could also be to punch them out to something like 1/4-20 or 28 (not sure if you can easily get SAE hardware up there), but really it's just bad design and needs more thread depth from something like a rivet nut.
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Look around for a small machine shop, the shop my friends have does stuff like this now and then when things are slow. If you have any shops like that in the area call around and see if any of them are interested. It's the sort of thing they could knock out using scrap material left over from another job.
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I would like 10 steel (exact alloy not important, it's for a desk) of about 50mm X 10mm X 2mm thick with two M6x1mm right hand tapped holes in them.
Do you think China is the way to go or should I look into local Montreal places?
quick to do with a hacksaw and a drill, but 2mm is very borderline for M6 threads
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Yes the plate is much more like 4mm thick. I call it a plate but it's much more like a strip.
I knew I was in trouble when I unscrewed the bolt and I felt it start binding towards the end of the travel, I knew it was damaged. The threads are clogged with material, guess I also need a M6x1 die.
Maybe there's some M6 screws I can buy but I wanna keep these.
I'm wondering if there's some industrial standard to this. The holes seem to be on 22mm centers.
edit: seems to be more likely to be M6X0.75mm screws, and in any case it looks like it's the threads in the screws that have been crushed, trying to re-tap them might not even work.
I just found some M6x1 bolts in my junk and they are coarser than the IKEA screws. Guess my visual estimates suck.
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Could it be that the screws have more damage than the threaded holes? You might try some new M6 screws.
If not that, would drilling and tapping the holes to the next larger size (M8) be an option? That would require new screws and enlarged through holes in the mating part.
Otherwise a thread repair kit (as previously mentioned) such as this:
https://www.amazon.com/XT-AUTO-Stainless-Compatible-Repairing/dp/B07KM1RQWP/ref=sr_1_6?dchild=1&keywords=m6+thread+repair+kit&qid=1627781826&sr=8-6 (https://www.amazon.com/XT-AUTO-Stainless-Compatible-Repairing/dp/B07KM1RQWP/ref=sr_1_6?dchild=1&keywords=m6+thread+repair+kit&qid=1627781826&sr=8-6)
I think new screws are in order regardless of the repair technique used.
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Yes the plate is much more like 4mm thick. I call it a plate but it's much more like a strip.
I knew I was in trouble when I unscrewed the bolt and I felt it start binding towards the end of the travel, I knew it was damaged. The threads are clogged with material, guess I also need a M6x1 die.
Maybe there's some M6 screws I can buy but I wanna keep these.
I'm wondering if there's some industrial standard to this. The holes seem to be on 22mm centers.
edit: seems to be more likely to be M6X0.75mm screws, and in any case it looks like it's the threads in the screws that have been crushed, trying to re-tap them might not even work.
I just found some M6x1 bolts in my junk and they are coarser than the IKEA screws. Guess my visual estimates suck.
afaikt the screws for jerker is M6x1, and anything else would be odd since that is pretty much standard
sure you haven't found some 1/4" bolts?
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Hmm. I guess it is M6x1 after all |O
I just now measured with my caliper, instead of my plastic ruler... :-[
I feel like buying so many things just for this ... it's nuts. There's these
https://www.ebay.ca/itm/142904968858 (https://www.ebay.ca/itm/142904968858)
-or-
https://www.ebay.ca/itm/183950150511 (https://www.ebay.ca/itm/183950150511)
-and-
https://www.ebay.ca/itm/265222402932 (https://www.ebay.ca/itm/265222402932)
:-DD
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I have a Jerker and don't recognize the broken piece. It's a great desk, Ikea should remake it, or I'd just make one from scratch with 2020 T-slot aluminum extrusion, after it collapses ;)
Sheet metal shops usually can't go that (4mm) thick and the piece has some welds. There's good shops in Quebec.
You could weld new nuts on the other side but the piece seems to be unrepairable.
Protocase (https://www.protocase.com) Nova Scotia can make heaven but I found them expensive.
Metal Supermarkets (https://www.metalsupermarkets.com) is okay for small pieces, usually in town.
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There's the Jerker workdesk and the Jerker computer desk, I have both. My problem is with the computer desk, the shelves that bolt on to the risers.
The reason this is a problem for me is that I also have the extension riser with an extra shelf. I got the desk on Craigslist years ago, and it looks like previous guy over-tightened everything.
(https://static.turbosquid.com/Preview/2014/07/11__05_22_16/jerker_img_000000.jpg29ca78cd-9458-47a7-bd62-cfc28327dec8Original.jpg)
This is the workdesk. Or bench, or whatever.
(http://photos1.blogger.com/blogger/6542/2156/1600/jerker.jpg)
It's a great desk, Ikea should remake it,
:-+ :-+
IKEA is fantastic at coming up with great products and dropping them. It's part of the experience. I just bought a few Kallax units to store my endless trash and now I'm sure IKEA will drop the entire line within six months...
You could weld new nuts on the other side but the piece seems to be unrepairable.
If it is buildable, it's repairable. But yeah, there's always some sort of Achilles Heel somewhere. It's all heavy tubing and thick metal and dense particle board and a tough surface ... with this weakness.
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That is absolutely mangled. I would guess crossthreaded..
Buy an M6 tap and some new screws and it might just tidy up. If not, enlarge to M8 - you'll need a tap and a 7.5mm drill, and some patience.
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That is absolutely mangled. I would guess crossthreaded..
Buy an M6 tap and some new screws and it might just tidy up. If not, enlarge to M8 - you'll need a tap and a 7.5mm drill, and some patience.
M7 is also a thing thought not so common
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Another option that *may* be easier to obtain in North America would be 5/16-24 UNF bolts and a tap and clearance and tap drill bits. For the tap drill you need a .2720 ‘I’ bit, or 6.8mm or 6.9mm metric. However there isn't a lot of 'meat' in the ends of those plates so tapping out the holes for even a slightly larger bolt may not go so well, then you've got the PITA of drilling out the frame.
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Have you contacted IKEA and asked if they can provide replacement plates? At the local IKEA i have got spares several times.
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Have you contacted IKEA and asked if they can provide replacement plates? At the local IKEA i have got spares several times.
They will mail you spares for current catalog parts. The Jerker series was dropped about 15 years ago, they replaced it with the Fredrik series which IMO is inferior. I have a Fredrik and while it's still much better than average, it's weaker and smaller than the Jerker. The Fredrik uses simple "tab A into slot B" for the shelves and therefore no bolts.
And in any case, the Fredrik was also dropped years ago.
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You may be able to fix it with new bolts of reasonable quality and a thread forming tap. Thread forming taps do not cut the thread but reform the metal. Here is an example: https://www.ebay.ca/itm/352725227441 (https://www.ebay.ca/itm/352725227441) (use a good lube to aid reforming threads)
Thread forming screws are also available with similar thread pattern as the taps and if you can find such would probably suffice for a few uses.
Both the Ikea screws and the steel they were threaded into are very soft.
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Alex,
First I am somewhat new to this BB and hope it is OK to offer to do this work for you here. In addition to electronic shops, I also have a machine shop. The nut plate, by itself seems to be dead simple and easy to make. For that alone, I could make ten of them for about an hour of time and the cost of the materials. I am in the US in Texas and do not know about shipping to Canada.
But from your photos, it appears that the nut plate mounts to either the uprights or some other member of the desk and that mount is more messed up than the nut plate itself. They appear to be welded together. So, do you have a way of attaching the new nut plates? Perhaps additional holes in an angle bracket so it could be bolted together. Or do you have a local welding shop which can do the work? This may determine the type of steel used as some alloys will be more suitable for welding.
I would also need some better photos showing exactly where and how they are used so I could be sure the new ones would be suitable. Otherwise, you would have to assume all responsibility for that.
Also you appear to need new screws. I could provide them, but would need to know more about them; mostly the exact length needed. And would a different screw thread be acceptable or must it be the same, M6 thread as the originals. I have more M5 hardware than M6 and more English (inch sized) fasteners than metric.
Being new to this board, I do not see how to send a private message with my e-mail so we could communicate that way. If you are interested, perhaps you could send one to me with your e-mail.
Edit: I did manage to send a PM with my e-mail. Respond via e-mail address if you wish to continue.
Paul A.
Yes the plate is much more like 4mm thick. I call it a plate but it's much more like a strip.
I knew I was in trouble when I unscrewed the bolt and I felt it start binding towards the end of the travel, I knew it was damaged. The threads are clogged with material, guess I also need a M6x1 die.
Maybe there's some M6 screws I can buy but I wanna keep these.
I'm wondering if there's some industrial standard to this. The holes seem to be on 22mm centers.
edit: seems to be more likely to be M6X0.75mm screws, and in any case it looks like it's the threads in the screws that have been crushed, trying to re-tap them might not even work.
I just found some M6x1 bolts in my junk and they are coarser than the IKEA screws. Guess my visual estimates suck.
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Howdy Alex,
I think this is the kind of thing you should be able to fix.
If your apartment isn't the place for cutting and drilling metal, consider finding a Makerspace.
This one is in Montreal:
https://www.heliosmakerspace.ca/ (https://www.heliosmakerspace.ca/)
(I don't live in Montreal - any more - and I don't know anything about this particular place, just figured I could pass on the idea and see what you think.)
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Found a decent set of metric taps and dies at the local hardware store. Figured it can't hurt to try to redress the threads: seems to work.
I wonder how much weaker the retention is now. Guess I over-thought the whole problem because I didn't have a set of taps and dies before.