For the past 2 days I have been searching and searching for any peace of information that can explain the bold type face on the edge of this 2010 P Sacagawea Haudenqsaunee Dollar. I have compared it to other of its like in year however I am having a challenging time finding the same mint of the 2010 year. In any event, until I can find another of its like I am left puzzled. Maybe someone out there has a bit of insight. In the images the top coin is the one obviously in question. As for the faces of the coin, there are no significant difference between the coins.
Brand new lettering segment dies, most likely. Or the mint employee set the edge lettering machine up wrong. Or the planchet is slightly larger than the setting on the edge lettering machine. The collar may have been worn and allowed the coin to expand a .001 inch or so. I'm sure there may be a couple more reasons why the edge lettering differs from coin to coin. https://www.schulergroup.com/major/...k_platine_randpraegemaschine_rs_50/index.html
The obverse and reverse pics may or may not shed light on your question. All three sides tell the tale.
I'd say just the opposite, worn edge dies and they increased to pressure to sink them a little better. The lettering on new edge dies show the lettering to have a "chisel" type top surface. As they wear they lose that sharp chisel and become just flat letters.
The most likely explanation is that the spacing between the lettering die and the spinning impeller was closer than in your comparison specimens. While there are 4-5 font variants that have been identified among edge lettering, this doesn't appear to be a factor here.
