From where I might be able to source some 1300 micron (1.3mm) mild steel sheet?

[John Smith 47Participant @johnsmith47]

Hello

Can you suggest from where I might be able to obtain some 1300 micron (1.3mm) mild steel sheet?

I only need a small piece of say 10x10cm. Other grades of steel would be acceptable so long as they are highly magnetic (i.e. ferromagnetic).

It seems that although 1.3mm thick steel sheet does exist, the nearest standard sizes are 1.0mm, 1.2mm or 1.5mm.

With thanks

J

[John Smith 47Participant @johnsmith47]

[Anonymous]

Wonderland?

Low carbon steels, such as mild steel, aren't particularly magnetic. Electrical and transformer steels have much higher permeability and are likely to be available in a wider range of thicknesses than bog standard cold rolled sheet.

Andrew

[Michael GilliganParticipant @michaelgilligan61133]

There is some [much more than you apparently need] listed on ebay: **LINK**

https://www.ebay.co.uk/itm/143924260266

I have no idea how accurate, or flat, it might be … but it’s a start.

MichaelG.

[Bob StevensonParticipant @bobstevenson13909]

One of the best ways to source thin steel is to look around for a discarded stainless item,….i have a little collection of thin stainless steels from about 0.75mm to approx 1.5mm, all reclaimed from such items as a dishwasher casing,…the left over chimney cover for a kitchen extractor,..stainless shop sign and a scrapped pedal bin. All very useful and effectively 'free', most have polished surface.

[not done it yetParticipant @notdoneityet]

Posted by Michael Gilligan on 19/10/2021 15:19:38:

There is some [much more than you apparently need] listed on ebay: **LINK**

https://www.ebay.co.uk/itm/143924260266

I have no idea how accurate, or flat, it might be … but it’s a start.

MichaelG.

Collection only. I hope he gets the right hook!

[John BaronParticipant @johnbaron31275]

Hi John, Guys,

Try an old computer case panel !

[John Smith 47Participant @johnsmith47]

* Andrew –

Are you an expert in magnetism? Because if so I'd love to pick your brains!

I am almost instantly at the limits of my knowledge… but in my experience 'magnetic permeability' isn't normally the problem!

I'll get shot down for this, but loosely speaking 'magnetic permeability' means "how easily you can start to induce ferromagnetism within a material".

Whereas a much more important metric in practice is what is the maximum density of ferromagnetism that can be induced within a material? I think this metric is called the "Saturation Flux Density".

For example, in my experience if you put a permanent magnet up to some Mumetal (a Magnetic Shielding Alloy – e.g. Ni80/Fe15/Mo5 ) although it may have an extremely high magnetic permeability (e.g. 60,000+ H/m) the magnetic pull is about 1/4 that of mild steel – hopeless!

You are correct that there HAS to be something better than cheap mild steel, but from what I could see, it may not be very much better at creating a strong magnetic pull next to a static permanent magnet.

That's about all I know… But last time I looked into this I found it seriously hard to research this topic.

* Michael – yes I saw that listing and am trying to find out what thickness of mild steel he is really talking about. (The listing reeks of click-bait as it is confusingly entitled "1.3mm mild Steel sheet. aluminium stainless plate sheet 2mm 3mm"!!) And yes, "collection only" …would only happen if I am completely desperate!

* Bob – Although various grades (from memory grades 410 to 430?) of stainless steel ARE magnetic, my understanding is that stainless steel is always less magnetic than mild steel. I guess that this is partly due to the high Chromium content. Some grades (e.g. grades 301 to 309?) are categorised as "austenitic" and aren't magnetic at all.

Cheers

J

Edited By John Smith 47 on 19/10/2021 16:40:11

Edited By John Smith 47 on 19/10/2021 16:41:19

[Dave SParticipant @daves59043]

Steel shim stock is widely available, and precise in thickness

Google will find you a supplier

Dave

[Rod RenshawParticipant @rodrenshaw28584]

John

I am not clear what you mean by "strongly magnetic."

Ferromagnetism (as I understand it) divides into:-

"Hard" – meaning it retains it's "magnetism" " permanently" – like a horseshoe magnet, sometimes called a permanent magnet.

and "Soft" – meaning it is attracted to a magnet but is not magnetic itself unless it is close to a permanent magnet – like soft iron which you could pick up with a horseshoe magnet but otherwise it just sits inertly on the bench.

Which you need is going to determine the suitable type of steel, and perhaps where you could get some from.

Rod

[John Smith 47Participant @johnsmith47]

Dave:
> Steel shim stock is widely available, and precise in thickness

It would be fine to be high carbon/spring steel, but like I say stainless steel is best avoided.
Either way I can't find any "steel shim stock" of any sort that is 1.3mm thick (i.e. 50, 51, 52 thou)

Rod:

> I am not clear what you mean by "strongly magnetic."

I mean strongly attracted to a permanent magnet.
Perhaps curiously, I don't care whether it is "Hard" or "Soft".

I am working on a kind of magnetic latch. Although this is a simplification, what is going on magnetically in my design is not unlike what is happening in this latch:

i.e. The steels are held in a fixed position relative to a permanent magnet beside them. Fwiw, my magnet will be neodymium though. The magnetism of the permanent magnet itself will of course need to be "hard", but all that matters with the steels is that they channel the magnetic flux effectively.

So I think you would probably say that the magnetism in the steels should be "soft"… but to be more accurate whether or not the steels retain their magnetism doesn't really matter either way, because if they ended up becoming to some extent permanently magnetised – magnetised in line with the permanent magnet that is – that wouldn't matter. In fact it if anything might even help… (??)

J

[peak4Participant @peak4]

If you're cutting it down and can get by with ½" wide, you could try HERE
https://www.repco-tech.co.uk/shims

Bill

Edited By peak4 on 19/10/2021 19:22:37

[John Smith 47Participant @johnsmith47]

 

Most mild steel is 1.0, 1.2 or 1.5mm thick.
Most shims seem very thin.

Nonetheless, though slightly rare 1.3mm IS a standard thickness of mild steel.

Either 50 or 51 or 52 thou of an inch would do me.

 

Edited By JasonB on 19/10/2021 19:36:02

[peak4Participant @peak4]

Posted by John Smith 47 on 19/10/2021 19:20:17

It would be fine to be high carbon/spring steel, but like I say stainless steel is best avoided.
Either way I can't find any "steel shim stock" of any sort that is 1.3mm thick (i.e. 50, 51, 52 thou)

………..

 

Ah, so it doesn't really need to be 1.3mm
18 Gauge equates to 50 thou I think See Wiki
https://en.wikipedia.org/wiki/Sheet_metal

Be wary though as other sources list it as 48 thou, so those that say 50 might just have rounded it up..

Obviously this is more than you need, but maybe food for thought.
https://www.ebay.co.uk/itm/402689752952?hash=item5dc22dff78:m:mCP8WeBThOlx1fV-SzLwLVg

Bill

Edited By peak4 on 19/10/2021 19:57:16

[John HaineParticipant @johnhaine32865]

Why does it have to be 1.3mm? Part of the art of design is to use easily available standard components and materials as far as possible.

[malcolm wright 3Participant @malcolmwright3]

These days sheet steel is generally below nominal thickness, so 1.5mm sheet would actually be 1.4mm.

[Rod RenshawParticipant @rodrenshaw28584]

John

Now that we know a little more about the application:-

Of the common materials, soft "steel" will be attracted most strongly ( High permeability), and the less carbon the better. Stainless steels are not so good, as you have said.

A harder steel (more carbon) will not be attracted quite so strongly but the difference may not be important. But a harder steel will probably have more remanence, ie it will tend to become a magnet itself under the influence of the permanent magnet, especially if there is movement between the 2. But you said this does not matter. The essence of a latch is that it opens and closes so perhaps the build up of residual magnetism will affect the operation in time.

So, very soft steel, or soft iron, alternative names for nearly pure iron. perhaps a lamination from an old transformer might be close enough in thickness. Your drawing does not make it clear why the thickness is so critical.

Obtaining such small amounts of such material of a particular size may not be easy and some adaptation to the design may make life easier.

Rod

Edited By Rod Renshaw on 19/10/2021 20:55:54

[JasonBModerator @jasonb]

If you could find a friend or company with a surface grinder it would be easy enough to thin down some 1.5mm material

[John Smith 47Participant @johnsmith47]

Posted by peak4 on 19/10/2021 19:21:27:

If you're cutting it down and can get by with ½" wide, you could try HERE
https://www.repco-tech.co.uk/shims

Bill

Now we're talking. Thanks!

[John Smith 47Participant @johnsmith47]

Posted by John Haine on 19/10/2021 19:46:49:

Why does it have to be 1.3mm? Part of the art of design is to use easily available standard components and materials as far as possible.

Simply put, because all the other things that it has to be parallel to add up to 1.3mm. If I bought 1.5mm steel I would have a lot of work to do.

Furthermore once I have done some prototyping by hand do know exactly what we need, I will get some a number of parts cut by laser. But there is no merit in designing around a thickness that is difficult/impossible to obtain in greater bulk.

If 1.3mm mild steel turns out to be "almost impossible" to obtain I would be better off designing around the problem in some other way, but it would be rather messy…

> These days sheet steel is generally below nominal thickness, so 1.5mm sheet would actually be 1.4mm.
Worth knowing. Yes, I find it deeply irritating how inaccurately made many raw materials are. They often come with terrible finishes too.

FWIW, I also had difficulty finding any 1.4mm mild steel!

[Michael GilliganParticipant @michaelgilligan61133]

Posted by peak4 on 19/10/2021 19:21:27:

If you're cutting it down and can get by with ½" wide, you could try HERE
https://www.repco-tech.co.uk/shims

Bill

.

That looks a useful Supplier, thanks Bill

[ noting that the minimum order value might encourage ‘strategic’ purchases ]

MichaelG.

.
[quote]

We have a £35 minimum order policy. Any orders under this value will incur an additional fee to adjust it to the minimum.

[/quote]

[John Smith 47Participant @johnsmith47]

Posted by peak4 on 19/10/2021 19:41:56:

Posted by John Smith 47 on 19/10/2021 19:20:17

It would be fine to be high carbon/spring steel, but like I say stainless steel is best avoided.
Either way I can't find any "steel shim stock" of any sort that is 1.3mm thick (i.e. 50, 51, 52 thou)

………..

Ah, so it doesn't really need to be 1.3mm
18 Gauge equates to 50 thou I think See Wiki
https://en.wikipedia.org/wiki/Sheet_metal

Be wary though as other sources list it as 48 thou, so those that say 50 might just have rounded it up..

Obviously this is more than you need, but maybe food for thought.
https://www.ebay.co.uk/itm/402689752952?hash=item5dc22dff78:m:mCP8WeBThOlx1fV-SzLwLVg

Bill

Edited By peak4 on 19/10/2021 19:57:16

Well, within reason it need to be as close as possible to 1.3mm. But if 0.1mm out I suppose that web be fine, but not ideal.

Strangely enough, from what I can see for Sheet Steel, "Gauge 17" 0.0538in (1.37mm) would be closer than Gauge 18 – 0.0478in (1.21mm) – if that is you can find any!

…Though in this modern age, why the heck manufacturers continue to make it so darned complicated is totally beyond me. Also those tolerances are jaw-droppingly imprecise. For 18 gauge steel sheet it appears to be +/- over 8%! You have to wonder how the heck does anybody in manufacturing industry manages fabricate any useful products out of that mess! Bonkers.

[John HaineParticipant @johnhaine32865]

Posted by John Smith 47 on 19/10/2021 21:16:50:

…..

…Though in this modern age, why the heck manufacturers continue to make it so darned complicated is totally beyond me. Also those tolerances are jaw-droppingly imprecise. For 18 gauge steel sheet it appears to be +/- over 8%! You have to wonder how the heck does anybody in manufacturing industry manages fabricate any useful products out of that mess! Bonkers.

It's called "engineering" John. Designing within the constraints of materials and components that can be sourced at an appropriate price.

[speelwerkParticipant @speelwerk]

The closest I can find has a thickness (starke) of 1.25 mm, dimensions you can select from 50×50 mm minimum. Hope your German is up to date but they write that it is magnetic and do deliver to the UK. **LINK** https://www.metallparadies.de/stahlblech-glatt-0-75-6-0-mm-staerke-bis-2x1m.html Niko.

[John Smith 47Participant @johnsmith47]

Posted by Michael Gilligan on 19/10/2021 21:00:34:

Posted by peak4 on 19/10/2021 19:21:27:

If you're cutting it down and can get by with ½" wide, you could try HERE
https://www.repco-tech.co.uk/shims

Bill

.

That looks a useful Supplier, thanks Bill

[ noting that the minimum order value might encourage ‘strategic’ purchases ]

MichaelG.

.
[quote]

We have a £35 minimum order policy. Any orders under this value will incur an additional fee to adjust it to the minimum.

[/quote]

These sort of unfriendly barriers are actually pretty much out of date. I have talked to a few small-scale manufacturers and they seem to be quite irritated by this sort of thing.

It seems to me that to a quite a large extent the whole world is just thundering onto the likes of Amazon and the old tidy structures of wholesaler / distributor / retailer etc are just being crushed.

 

Edited By John Smith 47 on 19/10/2021 21:37:02

[Author]

Posts