* .stl to iges format

Well, not exactly what you asked for, hopefully this is helpful nevertheless...
I converted the STL file (using our https://instepstudio3d.com/ application) into two STEP files, the first one is simply a 1:1 conversion, basically taking any triangles and converting them to a planar feature.
The second file is a bit more along the lines of something useful, it performs automatic feature detection to convert whatever shapes it can detect and then stores that... but the underlying geometry has some faults, so the results will depend on how well your CAD application can heal the resultant shapes.
Other options would be possible too, but that is more than just a quick conversion.
Note that the wFeatures file contains errors that were introduced based on the original data...

Dear Ben Masefield,

Thanks for your help,
I am using inventor 2010 that I want to open this file in and modify, scale.. a little (as a solid)

Kind regards,

Phil

Dear Ben Masefield,

Thanks for your help
I have load the data and got imported components..But they very rough, circles shape are imported as polygons..and data do not have complete..

So I am going to draw it by myself

Thank-you very much for your help

Kind regards,
Phil