>> rather than BOLT01, BOLT02, BOLT03

Solidworks (and others eg. Geomagic Design, Catia, Creo, etc) do this because how they process data. If you have an assembly in Solidworks and add a bolt from a library you can pattern the bolt as you like, the BOM will indicate x number of bolt one are in your assembly.

This doesn't work when importing a step assembly. The software will read each bolt as a single entity, thus creating bolt 1, bolt 2, bolt 3, etc even if they are all the same.

This will impact your BOM too as each bolt will register as a separate entry i.e. 1x M10x30, 1x M10x30, 1x M10x30, 1x M10x30, 1x M10x30, etc. I get this all this time with imported step assemblies.