[TheForge] Identifying metals

[Bruce Freeman]

And if you're limited by lack of those things, use Archimedes' approach:

The volume of an object can be measured by the water it displaces.  Fill a bucket, drop in the metal (no splash) and catch and measure the overflow.  The volume of the overflow equals the volume of the metal.

Next use a simple balance beam to weigh the metal versus water.  This gives you the weight of the bar in terms of the VOLUME of water.

Now divide the first second water volume by the first water volume (clue:  the number will be >1) to get the specific gravity.  Specific gravity is essentially in units of g/mL (= g/cc =  kg/L).  Divide by 27.68 to get pounds mass per cubic inch.  

(The "pound" is really a unit of force, not mass.  Hence, I say "pounds mass" to indicate I mean the mass that exerts a downward force of one pound in a 1-g gravitational field.)

After you do this you're required to run naked though the streets of Athens shouting' "Eureka!"  (It's traditional.  Kinda like standing for the Hallelujah Chorus.)

Bruce
NJ


>>> Hochewa at aol.com 10/5/2005 7:44:55 PM >>>
 
To All,
If the bar is regular in shape and if you have a fairly accurate scale, try  
to determine the density of the alloy.  Monel should have about the same  
density as copper, i.e., .323 pounds per cubic inch.  Any of the super  alloys 
will be .3 or less.
 
Hochewa.
 
In a message dated 10/5/2005 5:03:41 P.M. Eastern Standard Time,  
jonned at hvc.rr.com writes:

Hi  all,

Have a question about some mystery metal I picked up.

I  have a bar of a heavy metal that I thought was cold rolled steel. The  
outside surface is a grayish bown color from age, and is silvery on the  
inside. I forged it hot under a power hammer and it is tough, moves ok but  
is hard. I was about to try to do a test hardening when I found it was  
non-magnetic, totally.

My guess is that it is monel, but don't have  a way to narrow it down. Any 
suggestions?

Jonathan  




_______________________________________________
Manage membership or unsubscribe at:
http://mailman.qth.net/mailman/listinfo/theforge 
theforge mail list group photo site is
http://www.photoaccess.com 
Login:  blacksmithblacksmith at hotmail.com
password:  anvil
___________