I need some fence panels replacing, the posts will need to be installed using bolt-down supports since they are going onto a concrete driveway. The supports I bought come with concrete screws, but the installation man wants to use his own screws. I've looked at the box they're in and his screws are described as 'ideal for light to medium-duty fixing.' Surely they aren't the right screws for fence post supports then?? Am I right to say no thanks to his screws?