Magnetic Lock

[keysman]

Miwa lock of Japan uses magnets in place of pins in many of their locks.
They are considered "High Security and most do have a UL 437 listing

They make a pin tumbler/mag version also.

Interesting thread.... there is reliable a method for picking MIWA (damage free opening without the correct key) I would think a varation of that method would be quite effective on that padlock

I may post something in the advanced area.

There are frequently Miwa locks on e-bay, if any one is looking for a new challenge.

[Kaellman]

Never gotten my hands on a magnetic lock, but im actually planning on building a magnetic pick, just for the fun of it. I got the basic idea from a website. Ill post a description and some pics in the automatic/mechanic forum in a week or two.

[raimundo]

niobium or is it nyobium or niobyum will screw up your tv screen, store it in the case with floppy discs.

[NKT]

I've got several Bloody Powerful Magnets(TM) and they are quite scary. Although only the size of a little finger nail, they will hold each other through your hand. The smallest ones I got from Claires Accessories for £1 for ten, they are used for magnetic earings (they hold through your ear without a hole)

The biggest ones I use a polishing disc to stop them getting too close, as you cannot split them without serious effort - I use a steel vise, close it on them, then open it, whilst using a knife blade to split them a little. They beat the anti-backlash spring in the vise, but not the screwthread, and so you can split them like that.

Awesome power. Stops your watch, pulls metal through paintwork or plastic, and pinches your fingers badly if you let them.

[toomush2drink]

The smallest ones I got from Claires Accessories

Never really gone into that shop before

Is there something you want to tell us ?

[NKT]

Like I didn't see that one coming...

Yes, my cousin is a manager of one, and my gf loves it! :-Þ

I, however, have to make do looking for interesting stuff while they natter for hours about what the best earring or necklace is this week!

But ten little Neodymium magnets for a pound is great!

Imperial (Inch) Neodymium Rare Earth Magnets
Neodymium rare earth magnets are the strongest magnets by weight and have multiple uses in science, engineering, industry, magic and more. All our magnets have a maximum operating temp. of 80C & a Curie temp. of 310C; tolerance +/-0.05mm.

I cooked one whilst welding, and it is now only just powerful enough to hold it's own weight. They also don't like the damp, and tend to shatter against one another as they accelerate together, spalling small bits! You will never, ever get any iron filings off them, either.

[hzatorsk]

MCM:
The problem with these types of lock, is that the magnetic 'pins' can be spaced ( e.g.) NSNNSNSS in a very small area. A regular magnets' field is not concentrated enough to target a specific pin, hence Chuck's suggestion of a very strong magnet to pull all the pins at once.

Hope I'm on the right track here.

If not, I'm the one sat in the corner with a certain hat on.

My lock had pins oriented both ways as you suggest and a very strong magnet did not open it. My lock worked by repelling pins (not attracting them) and some pins will not repel at all by using a large strong magnet with a single orientation.

[MrB]

Repelling from one side is the same as attracting from the other side.

If you put a strong enough magnet on the opposite side of the lock, it could pull all the pins in the right direction to open it.

[hzatorsk]

The idea here isnt to manipulate the pins individualy, but rather to manipulate them wholesale. The rare earth magnet will be strong enough to pull all the magnets in one direction Just find the direction depending on the lock brand, and there you go.

Mick, yes a harddrive magnet may be enough.

Well... if you say so... It doesn't work in practice (at least it didn't on ly lock) as an incredibly strong magnet will not attract even a tiny magnet that is pole oriented incorrectly.

Loose pins (on a table for example) are indeed attracted by very large magnets... but only if they are free to reorient themselves first.

[Chucklz]

The little magnets are of the ferrite type no? Try sticking one to a harddrive magnet ,but with the "wrong" polarity. It works for me, but it does tend to weaken the ferrite magnet.

[mrfirebug]

Miwa lock of Japan uses magnets in place of pins in many of their locks.
They are considered "High Security and most do have a UL 437 listing

They make a pin tumbler/mag version also.

Interesting thread.... there is reliable a method for picking MIWA (damage free opening without the correct key) I would think a varation of that method would be quite effective on that padlock

I may post something in the advanced area.

There are frequently Miwa locks on e-bay, if any one is looking for a new challenge.

Boo! I won't have access to the advanced section for ages. Oh well, I guess if I ever get myself in there I'll be reading that post first.

On a side note, you are in there with only 20 posts? Impressive.

~Mike

[NKT]

Whether or not the little magnets will "give up" and be attracted depends on a number of things. The main one is the magnetic suceptability of the material.

Basically, if you get a bit of magnetic iron, you can easily overwhelm the little magnetic field and attract the iron. This is because it is a "soft" magnetic material.

If it is a rare earth magnet, you won't be able to do this. The rare earth magnet isn't magnetic in the first place, and so can never be overwhelmed and attracted.

Also, a good design will have taken this into account - it is much like the "overlifting" of pin stacks. It should never have happened, but it did sometimes. This would be (comparably) the same flaw in a magnetic lock.

[Kayvon]

I think I recall reading something in the 2600 FAQ that talked about these. If I remember correctly, it said it was possible to create an electromagnetic powered by an alternating current (like the AC from power outlets which, in the US, change directions and back again 60 times per second) and use the alternating electromagnet to "pick" the magnetic lock. I've never tried it myself, so take it for what it's worth.

[NKT]

It would have to be a light magnet and a heck of a force for it to oscillate at those speeds!

120 motions a second is a real lot for a physical thing, and hitting the end stops would probably turn a rare earth magnet (back) into dust.

Kind of like a pickgun for magnetic locks, but I don't think it would work on a good design.

[sixit]

This is an older thread, but I couldn't help but reply. I loved the replies involving physics and varying magnetic tricks to defeat this lock. I had one of these trinket locks about 15 years ago. They cost about $8 back then.

Do you all remember a supposedly real-life story where a tractor-trailer got wedged in under a bridge, and police talked with engineers about the best way to unstick the truck? They considered getting a cutting torch and cutting away the top of the truck, they considered getting a huge towtruck to pull it, and so on and so forth. All the while a young daughter of one of the engineers, who happened to be with her father when the emergency call came it, patiently tried to get the attention of the emergency crews. Finally, she did; the silence was deafening when she calmly asked why didn't they just let the air out of the tires.

I love that story, and since learning of it have used it many times when I find myself overanalyzing a problem; something I do exceedly well and far, far too often for my wife's tastes. Had I not owned one of these novelty locks a long time ago, I would have joined the lively physics discussion. Alas, there is a far more boring way to defeat this particular lock: use the butt of a screwdriver to tap on the lock while pulling gently on the shackle, if memory serves. It opens almost instantly since the tolerances are more fitting for bumper car races than for NASCAR races. In fact, if memory serves, I think simply shaking the darn thing opened it.

It's an intriguing idea, to create a purely magnetic padlock, but this particular lock isn't anything more than a novelty.

Cheers,
Robert Reese~