US Pennies compositions & TID's on the CTX3030

maxxkatt

Forum Supporter
Joined
Sep 20, 2015
Messages
3,485
Location
North Atlanta, GA
Ever wondered why pennies ring up so differently? Well you probably knew, but here are some more detailed results tested on the CTX3030 in the Ferrous-coin mode with the pennies on a patch of ground cleared of any other metal.

You can easily see from the data that the TID values change when the composition or weight changes.

You are correct. 62-82 has .950 copper and .05 zinc. no tin. oops on my part copied it down wrong. Mad a mistake and Cudamark caught the mistake.
 

Attachments

  • pennies us air test on ctx3030.jpg
    pennies us air test on ctx3030.jpg
    43.9 KB · Views: 206
Last edited:
I actually just tested an 1862 fatty and it is indeed a 12-24. That’s pretty astounding. I had found that coin a couple years ago with the CTX in an old town hall lawn, but didn’t recall it being that low. I guess if you’re somewhere old…gotta dig a lot more of a range to get that kind of thing!
 
I believe a Flying Eagle is the same composition as the 1859-1864 Indian. I just did an air test and it came in at 12-24 as well.
 
I actually just tested an 1862 fatty and it is indeed a 12-24. That’s pretty astounding. I had found that coin a couple years ago with the CTX in an old town hall lawn, but didn’t recall it being that low. I guess if you’re somewhere old…gotta dig a lot more of a range to get that kind of thing!

I think you told me as they go deeper, the CO and/or FE change. So I mentally make that adjustment.

I have opened up my CO values a little more to the left to include the Indians. Since I am digging deeper than 4-5" with my CTX I might was well dig Indians. I think they are cool.

I did not have the 1859 and 1862 test so I bought them on Ebay so I could air test them. I guess those are called the Fatties since they weigh more. I am just guessing that at least on these pennies, the differences in weight and compensations account for different TID readings.

I know it is a little arcane knowledge, but I always wondered about pennies and why the rang up different. Of course every one know about zinc memorials and shields.

*********** more corrections ********
Ok, lots of corrections here. I should not have created this chart from the very small print out of "A Guide Book of United States Coins 2019 by R.S. Yeoman, 72nd edition when I had this head cold and taking NyQuil.

Here is the corrected file. I hope I got it right this time, I don't wish to mislead anyone with bad info.

The test was an air test on ground I cleared with my CTX3030 to make sure no other metal items were in the ground. Height was about 7" above the ground using Ferrous-Coin mode. My ground is moderately mineralized but that should not have affected anything since it was an air test.

Sorry for the goofs.
 

Attachments

  • pennies us air test on ctx3030.jpg
    pennies us air test on ctx3030.jpg
    39.4 KB · Views: 171
Last edited:
Those looks about right in regards to comparing your results to what I've observed with my E-Trac when digging up pennies in the ground.

Zincoln's usually ring up in the mid to upper 30s and copper pennies usually in the low to mid 40s. These are CO numbers, of course, not FE.
 
Great reference for pennies/cents....in my experience IHP ring up somewhere around 11-39 (Washington state ground) and wheats are normally hovering right at 12-40/41.

One of the reasons I do not dig many IHPs with the CTX is that it is very hard to distinguish between a Memorial and an IHP and I have found I rely heavily on the depth over tone.

A side note: While it happens occasionally, I don't dig many Memorials that are 12-43. That is typically a dime (silver or clad)

Finally, VID readings are notorious for being +/- what is printed due to ALL the other factors:
- Soil
- Speed
- Coil tilt
- Moisture
- etc.

Great resource regardless!! :thumbsup:
 
I have heard that you can't take "copper" (as an ingredient) to necessarily be exactly the same, as the decades rolled onwards.

Uncle Sam bought copper and silver and gold from the "open market" @ wherever it was being mined, at the time (Utah, NV, Idaho, etc....). And there are slight geographical impurities that can effect our TID's in the different locales.

For example "rose gold" and "yellow gold" are both "gold". Yet subtle impurities can skew TID's.

Which is why wheaties from the 1950s versus wheaties from the 1910s read differently. Even though containing supposedly the exact same ingredients.
 
I just looked up the composition of early fatty Indians recently , and why they I'd lower than the later thinner Indians...I guess it's the nickel that was in them that drops the ID
Flying Eagle cents 1856-1858 and Indian Head Cents 1859-1864 were made up of 88% copper and 12% nickel.
 
Back
Top Bottom