Frame Head Screw (Purlins)
Frame Head Screw (Purlins) are self-drilling type screws intended to fasten metal roofing and siding to wood purlins. Stitch screws are designed specifically to fasten overlapping panels together.
The washer serves to attract rubber EPDM washer when driven at an angle. Threads change from fine to coarse to create better strength in different wood substrates.