"Quite simply these screws are not up to the job. Initial impressions looked good and they do at least start well, but very soon into the drive most simply start to deform and bend. I gave these to my builder for our new hardwood decking and despite pre-drilling all holes, within 10 minutes he'd given up using these as they'd either bent halfway in or sheared off. I thought he might have been exaggerating the problem until I tested them for putting up some softwood fence panels and even in this undemanding situation they were failing in a similar manner. I'll be taking these back for a refund."