A magnet sticks to my new Silvia !!!!

[Rodders]

I am impressed so far with my new Silvia but one disappointment is the fact that the Stainless steel may not be as high grade as I expected.

The front, back and sides attract a fridge magnet strongly. The drip tray underneath and perforated drip tray cover do not attract.

Interesting, Rancilio cutting costs maybe? or has this always been the case, maybe we can get a few coffeesnobs to do the very technical magnet test on their Silvias to compare.

Ironically the magnet holds stronger to the Silvia than my Chinese made Sunbeam EM6910 but maybe that is due to a heavier gauge stainless steel.

[beanflying]

Re: A magnet sticks to my new Silvia !!!!

Some Stainless Steels are magnetic. Not a sign of quality by a sign of which grade it is DONT PANIC slip on the peril sensitive sunglasses and enjoy the shine of Silvia for years to come 8-)

More reading here http://en.wikipedia.org/wiki/Stainless_steel

[WSullivan]

Re: A magnet sticks to my new Silvia !!!!

Nothing to worry about, when i had my silvia, it was not magnetic from memory, i had to stick a timer to it, the magnet would not stick.......

Thought the following article was written pretty well, in laymans terms......from here.





Magnetic knife racks might be good for hanging up your knives, just dont try throwing your kitchen sink at one.

Although knives and kitchen sinks are both made of stainless steel, theyre made of different combinations of alloys so they have different magnetic properties.

Stainless steels are alloyed steels, says materials engineer Professor Veena Sahajwalla from the University of New South Wales.

As well as containing iron and carbon, like plain carbon steel, they also contain other components which give the stainless steels superior properties for different applications.

For example, knives are most likely from the 400 series says Sahajwalla, a family of stainless steels that also contains the metal chromium, which makes the knives more resistant to rust than if they were made out of plain steel.

Whereas the kitchen sink is more likely to be from the 300 series. These stainless steels have had both chromium and nickel added, and are easier to form and weld. Some of the 300 series steels also contain molybdenum, which further increases their corrosion resistance, and is why theyre often used in marine environments.

But unlike other grades of stainless steel, the 300 series is not magnetic.

The reasons for this come down to their structure.

At the atomic level in a material like iron, which has strong magnetic properties, all the iron atoms are acting as mini magnets aligned in the same direction.

So cumulatively they are all adding to the overall magnetisation of the material, this is known as ferromagnetism.

But once you start adding other components to the iron, things get a little trickier.

"If youve added chromium and nickel," says Sahajwalla, "youve got a situation where these arrangements of atoms are clearly going to be different."

"Its going to not have that nice proper arrangement of atoms, which is what you need to have for good magnetic properties.

"If youve got anything other than that then eventually all these sorts of magnetic fields cancel each other out so the net sort of outcome is that [this type of] stainless steel is not magnetic."

So why then are 400 series stainless steels, which also contain chromium but not nickel, still magnetic?

"Thats because the atoms still have the ability to be aligned in the appropriate manner," says Sahajwalla.

However its not just what alloys are added to the stainless steel that determines its magnetic properties. Magnetism is also dependent on temperature, says Sahajwalla.

Even permanently magnetised materials like iron can lose their magnetic properties at high temperatures, in the case of iron at about 770°C.

This is because as you add more thermal energy to the material, the atoms are able to move about more randomly, says Sahajwalla, destroying the kind of order they had previously.

The reverse is also true: its possible to induce magnetism in some non-magnetic materials by working them at relatively low temperatures.

"Anything thats sort of squishing [the material] down or obviously stretching it out" can force alignment of the atoms, says Sahajwalla.

Professor Veena Sahajwalla was interviewed by Suzannah Lyons.

[gavin]

Re: A magnet sticks to my new Silvia !!!!

i met up with a client a couple of days ago who was inspecting some equipment my work was fabricating for them. One of the things agreed on was that all nameplates attached to the equipment must be in s.s. He put a magnet on a nameplate, it stuck to it and he declared "this is not stainless steel!" And I replied, "Yes it is, the magnet is pulling onto the painted carbon steel body underneath it, not the nameplate".

might be the same case here? Try detaching the panel form the machine and you might find the magnet wont stick to it anymore.

[beanflying]

Re: A magnet sticks to my new Silvia !!!!

pulling onto the painted carbon steel body underneath it, not the nameplate

Not nessecerily for the coffee machines but most likely in your case. Fairly likely your labels are 400 or 303 or 304 S/Steel.  A magnetic field will happily travel past a thin plate of Stainless Steel anyway.

Without going into heavy discussions on materials science the basics are 400 series stainless steels (cutlery is one of these normally) are generally magnetic. 300 series are either low or considered to be non magnetic. There are exceptions to these and also ways in which some Stainless steels may become magnetic due to the manufacturering process which is work induced, basically it modifies the structure of the material.