Pots
Have 6 pots some are aluminum, some steel, others are shiny. they look like steel but a magnet won't stick. what are they? they are 15 years old (I. Goldberg's)
Could be stainless steel -- that's not magnetic.
Grumpy Ol' Pops
Hold onto dreams, for if dreams die, life is like a broken winged bird that cannot fly.
Thanks, is titaium lighter or is aluminumOriginally Posted by Grumpy Ol' Pops
Come to the PA Ruck and we'll let you play with some
Yes, stainless steel is magnetic. Go into your kitchen and take one of the magnets off the fridge and stick it on a knife blade and see.
Titanium is lighter than aluminum. Aluminum can be very shiny and it is not magnetic. If you look on the bottom of a pot, it often states the material. Titanium pots are generally only made for camping and they are relatively recent in manufacture.
The pot in your picture obviously has a copper or copper-plated bottom. It looks like the body is stainless steel. Copper is not magnetic.
Last edited by Appalachian Tater; 12-17-2007 at 14:31.
Aluminum is 1/3 weight of steel for same thickness.
Titanium is 2/3 weight of steel for same thickness.
In practice titanium stuff will b lighter than the others for the same durability,
but aluminum can be just as light if you don't mind dings and dents.
That pot looked like stainless steel with a copper clad bottom.
Many stainless steels are not magnetic.
There are basically 4 differents types of stainless steel:
1. Ferritic - pretty sure these are magnetic.
2. Austenitic - pretty sure these are not magnetic.
3. Martensitic - pretty sure these are magnetic.
4. Precipitation Hardenable - not sure.
To compare one would need equal volume of the material, thus comparing density:
Al density: 2.7 g/cm^3 (approx since there are different aluminums)
Ti density: 4.9 g/cm^3
source: http://edboyden.org/constants.html
Thus comapring densities Aluminum will be be lighter when compared to an equal volume of Titanium. The other variable to consider is whether one requires more or less volume to create the requisite structural integrity of the pot. This would be noticeable in the thickness of the pot material.
When we compare the modulus or strength of the materials:
Al is 7 x 10^10 Pa (N/m^2)
Ti is 1.16 x 10^11 Pa
So the strength of Ti is much greater than Al so one could get away with using less.
In the end since the only real metric one cares about is the end weight, just look at the weight of the pots and not the material it is made of.
1oz of Ti is the same weight as 1oz of Al.
Hmmm. All of my knife blades are magnetic. Do they use non-magnetic stainless steel in the manufacture of cooking pots?
Most SS knife blades are magnetic 'cause they have carbon (or some other alloy) in them so as to take and hold an edge. Something intended for salt water use will usually not be magnetic.
How would carbon effect whether or not its magnetic? I figured that the stainless steels that had other metals in them might not be "magnetic" in the sense that we are used to.
Stainless steel is a generic term, there are many different types. Basically stainless is a steel alloy with a certain percentage of chromium (to make is rustfree). Other metals are often added as well. For example carbon is added to increase the hardness, these alloys are magnetic. In some, nickel is added which modifies the structure of the alloy making it non-magnetic. Thus it is not the carbon which makes the SS alloy magnetic, it is the nickel which makes it non-magnetic.
Ruck
Wouldn't miss itCome to the PA Ruck and we'll let you play with some
Close. Its not the carbon that makes steel magnetic.
Its the Base-Centered Cubic structure of the Ferrite.
Martensite is a Base-Centered-Tetragonal, but is still magnetic.
Austenite is Face-Centered-Cubic, which seems to make it non-magnetic. On the downside they are no heat treatable, but can be cold worked for hardening and strengthening. Some precipation hardenable stainless steels might be non-magnetic. Not sure. Stainless steel that is primarily for corrosion resistance are most likely to be austenitic and therefore non-magnetic. Good stainless steel cutlery might be magnetic. I know my fridge isn't. Haven't checked by cutlery. Normal tableware cutlery might by austenitic. Stainless steel knives are not likely to be austenitic, so they are most likely to be magnetic.
Here are some examples of stainless steels of different types:
Ferritic:
409 - 0.08%C, 11.0%Cr, 1.0%Mn, 0,5%Ni, 0.75% Ti - Automotive Exhaust
446 - 0.20%C, 25.0%Cr, 1.5%Mn - Valves, Glass Molds, Combustion Chambers
Austenitic:
304 - 0.08%C, 19.0%Cr, 9.0%Ni, 2.0%Mn - Chemical and food processing
316L- 0.03%C, 17.0%Cr, 12%Ni, 2.5%Mo, 2.0%Mn - Welding Construction
Martensitic:
410 - 0.15%C, 12.5%Cr, 1.0%Mn - Rifle Barrels, Jet Engine Parts
440A - 0.70%C, 17.0%Cr, 0.75%Mo, 1.0%Mn - Cutlery, Bearings, Surgical Tools
Precipitation Hardenable:
17-7PH 0.09%C, 17%Cr, 7.0%Ni, 1.0%Al, 1.0%Mn - Springs, Knives, Pressure Vessels
From Callister, but adapted from ASM Handbook.
I'm guessing it would be carbon's hexagonal shape and the way it bonds to most everything it comes near. I'll admit I'm out of my league here, maybe a chemist/engineer can enlighten us.
I must say I have learned quite a bit today, prompted by this thread. Thanks, JAK.
Thanks to both Tater and Jak.
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