Is it a touchmark?

[Mac53]

Hello all!
My friend picked this up at the flea market today (he saw my rack of hammers and has been picking up any odd ones he sees since!). He wanted me to ID it and my first thought was that it was a touchmark. He said the edges seem like they used to be sharp, and that neither end has really ever been abused (seems in line with touchmark). Where I am confused is the name on it;
Wm Mann N
Phila

Any thoughts? Anyone know about the name?

[Aunt Phil]

Size of the stamp & the Phila stamp would more likely take me down the road of it being a shipyard inspector's stamp.
Huge Navy yard in Philly back when the US built a Navy.

Googling the name with ship inspector might yield results.

[51cub]

I only looked fast, so there could be alot more information out there. A very quick Google showed me a Wm Mann in Phila, that was a bookbinder, and stationer. It doesn't answer for me what that would be used for in that business, but it's a start

[turnnut]

my thought was a log marker !
 
to mark the ends of logs before shipping to the mill.

[bill300d]

My first thought too.