Anyone know what this is? It’s a 12 lb steel  ball about 5” in diameter. Pretty sure it’s not a cannon ball. It has 12 stamped in it. I was planning on drilling and tapping it to put an eyebolt in it for a hold down chain. Any help is appreciated. 

Shot put ball 

cast iron training/practice shot put.

shot put..   12 and 16lbs are common.. 

 

I think you'll find that a 12 pound weight for a hold down might be a bit heavy.  Try about 3-5 pounds for starters....jus' sayin'

cut it in half for 2 weights and you'll also be able to drill it easier

Funny thing though, a 12 pounder was a common cannon ball size...though a cannon ball would not be weight marked like that as it would throw the trajectory off.

I run into a lot of folks trying to sell ball mill balls as "cannon balls" for grossly inflated prices never realizing that cannon ball sizes were pretty standardized fo the last couple of hundred years and so it it doesn't match one of them it CAN'T be a cannon ball!  A couple of years ago I was at a local fleamarket and a guy was selling mill balls for US$1 apiece; I picked up several in decent shape and got a big laugh when the next isle over a fellow was selling them as "cannon balls" for $20 a piece.

What is a "mill ball"?

I mean I understand what a mill is, but my frame of reference is generally oriented toward grain milling (big stone wheel or roller mill). WHat sort of milling would the balls you reference be used for?

my understanding of mill balls are balls used to crush different materials into powders and also used in smaller sizes to act as a cleaning media in a tumbler.. 

This is my understanding but whos to say.. 

Search on ball mill; wikipedia has a good write up on them.

Ball mills and rod mills are used in the mining industry to pulverize ore before it is processed to extract or concentrate the end product, metal or other element or material.  The coarse rock is crushed down to gravel size and then put in a rotating drum filled with steel balls or rods and water.  The crushed rock comes out in a slurry to be further processed.  I'm here to tell you that rod and ball mills are LOUD.  The sound of an 8 foot diameter, 40 foot long drum about half filled with steel balls or rods rotating at 20-30 rpm is impressive.  Eventually the balls or rods wear down and have to be emptied out and replaced.  The worn rods are thinned out in the middle or broken into long, skinny cones and the balls are reduced in diameter but are still spheres.

"By hammer and hand all arts do stand."

Used to pulverize coal for the coal fired generating plants. V We have a steel plant near me that makes them "1/2"-4" for the mining industry"  I must check if I can get some cheap.

One more way to distinguish mill balls from cannon balls is that cannon balls have specific diameters (caliber).  The commonest size of cannon balls (US Civil War) are:

Weight            Diameter(caliber)

6 pounder =      3.67" (used mainly by the Confederates)

12 pounder =    4.62" (probably the commonest Civil War cannon using solid shot)

24 pounder =    5.82" (more commonly used in naval service than the army)

Also, solid cannon balls are cast from cast iron while mill balls are made of steel.  For most blacksmith uses steel is probably a better material.