Resolved the issue with 8 mm smooth rod fitting into the Oilite bushings

I ran into an issue 8 mm smooth rod fitting into the Oilite bushing.

1. The inner diameter of Oilite bushing is 8mm and the smooth rod (metric) is exactly 8mm. So the smooth rod doesn't go into the Oilite bushing. 
2. I bought 8.1 mm drill bit and i drill through the Oilite bushing and now smooth rod is moving inside the bushing. Issue resolved...

8 mm smooth is smoothly moving inside the bushing

Another view of 8 mm smooth rod + bushing