Looks like a sheetmetal hammer to me. I can't help on the maker, though. The only diamond co I could find only made farriers tools.
What is the size/weight? 'Diamond' is probably the Diamond Calk Company. They started making horseshoes and farriers tools but branched out into many other tools including their famous crescent wrenches and pliers. This is likely a farriers or blacksmiths cold cut tool.
Diamond Calk... became Diamond Tool... in 1963, according to online sources. Vaughan produced hammers for Diamond Tool, according to this brochure from Vaughan (see photo). So, perhaps Vaughan made that hammer. https://archive.org/stream/VaughanA... 125th Anniversary Brochure#page/n15/mode/2up
I will have to measure it tomorrow and update. Need to find a scale to weigh it. Thanks for the information. I think this kinda stuff is so fascinating. Finding something as simple as a hammer head. Cleaning it and looking into some history about it.
If this hammer-head is under a pound, it was usually called a "riveting hammer" in old catalogs, if it is two-pounds or more, then in old catalogs it is called an "engineer's or blacksmith's hammer. People these days are mostly not aware of riveting metal and things together, but in the early-mid twentieth century it was a major industry to make and use rivets. The metal-shop in our local school used to give us projects to make which required using rivets which were hammered with the peen of a hammer during installation. The larger hammers like this for general or blacksmith use were usually called a cross-peen style.
The length of this tool compared to its girth suggests it was struck by some other hammer and used as a cutter. The cutting tip may have been rounded over with time. Just a hunch.
If I can piggyback, I'm not familiar with this hammer type I picked up for 3 bucks. I think it may be for sheet metal? Put a jarrah wood handle on it. Pretty, pretty hard to work with, too. https://www.dropbox.com/s/x53pj6q229gon6t/20181010_025223.jpg?dl=0 Any info appreciated! ETA: It's Standard Tool Co., and the shape is exactly like a ball peen, but the eye in the head is quite small and instead of the ball peen it has a smaller flat face.
