Found this today..........

[bandroadman]

...............in extremely rocky soil here in Saginaw, Texas. More rocks than dirt. Using an AT Pro and rang in at 85 and about 6 inches down at a 45 degree angle and covered with big rocks. There is a ton of iron trash but this one rang clear as a bell and I thought I had a silver. I was hunting in coin mode with everything below 75 blocked out. Any thoughts as to why this happened? It is obvious that I am missing something, so any help will be welcomed.

 

[8720roger]

The tips of the blade is made of a different aloyd then the blade it's much harder that may account for the high numbers?

 

[glenn3-88]

On my at pro, steel will hit in the silver range. The depth you found it would indicate a coin possibly a quarter.
Even though it looks a little rusty, the ratio of rust to steel would overpower your disc of iron. To add to the
situation, you said you were in a lot of big rocks which could have blocked all but a tiny portion of the coil signal
to get in to it and send back only a small portion of the blade you found indicating again a small coin like object.
Just my opinion. Maby someone else has a better answer. Not a bad find though.

 

[senda]

Hi, I think not strong pulled the screw saw ....

Seriously, I have observed many times, with the maximum iron disc, a piece of iron with a size as the palm of a hand or more, and make sounds that way. I think the machine tells you that the size may be of interest. It happens just like you with ox horseshoes.
I think if you only use 75 numbers up you're losing many copper coins and other things that might be interesting. Silver not only man lives.
a greeting

 

[John-Edmonton]

Metal detectors are engineered to give the best probable conductivity based on a coin sized object. Pop cans and as in your case, a large metal objects can read as a good coin signal. What you can to, to rule out a junk target, is keep moving the coil back and forth while raising it. You will see that a large object allows a clear audio signal to remain active at a much greater ( higher) distance then say a penny. Also, if you pinpoint an object, you will see a larger area of audio verses a small target like a coin. This really becomes evident when using a concentric search coil and pinpointing off the inner front toe. Another reason why I prefer a concentric coil over a DD.

 

[Grilled Scallops]

John's right. Big things can identify as good conductors as would silver. You rule out large junk by using pinpoint.