To my knowledge, Simpson and USP's provisions for screws are limited to the use of their SDS-type screws, which are structural lags and are typically supplied with the hangers and anchors they're used with. They do not permit the use of deck screws (or similar) in joist hangers and lumber connectors.By the way, Simpson makes a wide range of galvanized steel connectors for framing elements. Although typically installed with special galvanized nails, Simpson has provision for use of screws as well. I don't really know how the IRC applies to use of screws with connectors, but as a professional engineer I spec screw connectors when I feel they are appropriate.
Per Simpson's 2008 catalog page 14:...Simpson has provision for use of screws as well.
That is simply not true. Many of their heavy beam hangers, hold-downs, and column bases do require the use of SDS screws (and many are supplied with those screws).But as I said, most of the Simpson connectors have specific provision for use of specific Simpson screws.