I don't see anything in the list that quite match the speciality of the shop. They sharpen a wide variety of blades, saw blades, drill bits, etc etc. (according to there website).

According to the same Wiki page you linked, we can use 'user defined' value if it's not in the list. I also found some people have used similar values to define this type of shop, although quite rare. https://taginfo.openstreetmap.org/keys/shop#values

I redefined the type to an english value that could be understood by more people I believe.