Greenstang

Welcome to the forum
We see these quite often on the forum.  
As Coinbuf stated, just a vise job or sometimes called a garage job.  
 Someone with too much time on their hands. A damaged coin now.

Welcome to the forum
That is not an error, it is damage  (PMD). There is no way for that to occur when the dime was struck.

Please do not use screen shots, they are too pixilated to see small detail clearly.   
From what I can make out, it looks like zinc rot, just another damaged zincoin.

Photos are a little dark to see detail but without even looking at it I could be 99.9999%  sure it is a counterfeit.  
This is probably the second most asked question on the forum and no one has found a genuine one yet.

The same as your 2008 nickel that is severe DDD from a very worn die.

Please do not use screen shots, they are too pixilated to see small detail clearly.   
From what I can make out, it looks like zinc rot, just another damaged zincoin.

The same as your 2008 nickel that is severe DDD from a very worn die.

That would be Die Deterioration Doubling (DDD)
In Mechanical Doubling the devices would be reduced.

The same as your 2008 nickel that is severe DDD from a very worn die.

Maybe it is just me but I do not consider die chips an error, it is a die event. It is no different than die deterioration or die polishing. The die has been altered and every coin struck after the chip started would have that mark. You could have tens of thousands the same until the die was retired.  Most errors are a one time event due to improper striking of the coin. If the die has a chip, then no matter how well the coin is struck, it would still show, it has nothing to do with the improper striking of the coin. 

Thanks for the new photo. The fact that the reeds are missing and the diameter is smaller confirms my thoughts that it is a dryer coin. This is not considered an error but damage to the coin.
Suggest if you are going to look for errors, read up on what constitutes an error. Sandon has given you some websites plus this is one I use frequently.  error-ref.com.

Maybe it is just me but I do not consider die chips an error, it is a die event. It is no different than die deterioration or die polishing. The die has been altered and every coin struck after the chip started would have that mark. You could have tens of thousands the same until the die was retired.  Most errors are a one time event due to improper striking of the coin. If the die has a chip, then no matter how well the coin is struck, it would still show, it has nothing to do with the improper striking of the coin. 

Maybe it is just me but I do not consider die chips an error, it is a die event. It is no different than die deterioration or die polishing. The die has been altered and every coin struck after the chip started would have that mark. You could have tens of thousands the same until the die was retired.  Most errors are a one time event due to improper striking of the coin. If the die has a chip, then no matter how well the coin is struck, it would still show, it has nothing to do with the improper striking of the coin. 

First, never hold a coin in your bare hands, the oil from your skin can cause fingerprints and greatly devalue a coin.
Also those are not reed marks, it is a pattern around the edge of your coin. It looks like the edge has just been worn down either intentionaly or unintentionaly.
Almost forgot, welcome to the forum

First, never hold a coin in your bare hands, the oil from your skin can cause fingerprints and greatly devalue a coin.
Also those are not reed marks, it is a pattern around the edge of your coin. It looks like the edge has just been worn down either intentionaly or unintentionaly.
Almost forgot, welcome to the forum

Maybe it is just me but I do not consider die chips an error, it is a die event. It is no different than die deterioration or die polishing. The die has been altered and every coin struck after the chip started would have that mark. You could have tens of thousands the same until the die was retired.  Most errors are a one time event due to improper striking of the coin. If the die has a chip, then no matter how well the coin is struck, it would still show, it has nothing to do with the improper striking of the coin. 

Looks like it might be a small delamination.   
Also a Struck Through is not a variety, it is an error. 

Would really need to have the size. It looks like a blank of some sort.

Looks like it might be a small delamination.   
Also a Struck Through is not a variety, it is an error. 

Common machine doubling.   
Also do NOT use screen shots, they are too pixilated to see detail clearly.

Why are you showing a 1946 cent and asking about a 1918 half dollar?
To answer your question, it would be around 7:30 on the Reverse.

Two types of 1942 Canadian Nickels
The first half of 1942 produced the regular 100% nickel 5 cent coins. Part way through in order to preserve nickel for the war effort, they switched to Tombac (a form of brass).  The twelve sides was to avoid confusion with copper cents. Tombac 5 cent coins were produced in 1942 and 1943.

Just noticed this now that you have had no reply.  
According to PCGS, there were 5 minted and 4 graded by them.

Early gold coins are among the most counterfeited of US coins.     
Going back to about 1853, gold coins hold 43 out of 50 top positions of the most counterfeited coins.

Just guessing here but it could possibly be an assayers mark verifying that it is gold.  
much like the trade dollars that were counterstamped proving them to be genuine.