In 'Boarders Away' by Gilkerson, it is mentioned that two Scandinavian axes were captured by the Americans from the British on Lake Erie during the War of 1812. It is surmised that the reason the Brits had these axes was that they were taken as naval surplus from the Danes during the Battles of Copanhagen (1801 and 1807). This practice of confiscating and reusing other country's naval surplus wasn't unique and was a common practice among nations. The navies of the world had not yet established model patterns until well into the 19th c, so there was leeway for such things.
Likewise, the Swedes and the Danish were at any given time friends or enemies, working together for a cause or attacking each other at sea. Along with the similarities between boarding implements, it is not a surprise that there was a cross-over of usage of these two country's boarding tools.
The key factor here was that during the period of 1790-1830, there was great chaos among the Scandinavian countries as they were attacked by the British, taken over by the French, etc. It is no small surprise that what developed from these uncertain times was a rise in privateering in the North Sea. Many countries, including the U.S, became victims as their ships were taken for 'attempting to bring arms to the British', France's enemy and thus Denmark's as well. This boarding axe might have seen such action aboard a privateer during this time!
https://www.napoleon-series.org/mili...rchant%20fleet.
https://www.stateoftheunionhistory.c...rivateers.html
https://listverse.com/2011/06/10/10-...the-north-sea/