Or copy this URL:
https://www.metalroofing.com/spirit/comment/7053/find/
That is a question one needs to ask the manufacturer. If you are in a wind uplift zone, then the product must be tested and approved. In addition, the manufacturer must have a QA program similar to ISO 9000 or better to ensure the materials are to the tested type and traceable.
Certainly I do not know of any assembly with screws into OSB sheathing that will withstand the high wind uplifts and certainly the screws need to be at least a #12 or even #14 in any case. Again ask the manufacturer. The same applies to the 1x4 fastening. One screw does hold more than in the OSB sheathing but needs to be a tested assembly as the screw head can pull through the metal.
Hope this helps.
11/8/2005
Dura-Loc Roofing Systems, Inc.
11/9/2005