Just recieved a package from Fred at BST with various ballscrews for my first build, nice smell of machine oil in the flat now. Giving them a twiddle it was immediately noticeable that a couple of them run a bit rough, like they've got swarf or grit in them, the others were fine - maybe not as good as Japanese/European parts I've felt before, but quite acceptable. Before I go and moan at Fred, has anyone else had product like this please? or do I need to clean them, and if so how? Thanks