Fastenere . 3SSTPP10100

SHEET METAL SCREWS HAVE SHARP THREADS THAT CUT INTO MATERIALS SUCH AS: <ul> <li>Plastic</li> <li>Plexi glass</li> <li>Wood</li> <li>And of course sheet metal</li> </ul> Sheet metal screws are also the go to fasteners for use with plastic wall anchors in drywall.<br> Tapping screws are considered externally threaded fasteners that "tap" their own mating threads in metallic and non-metallic (such as plastic) materials.<br> Tapping screws, especially Type A, are referred to as "sheet metal screws" because one of their first applications was in ventilation ducts made of sheet metal.<br> They also make excellent fasteners for attaching metal hardware to wood because the fully threaded shank provides good retention in wood.<br> Pan heads are slightly rounded with short vertical sides. A Pan head provides a low large diameter head, but with characteristically high outer<br> edge along the outer periphery of the head where driving action is most effective for high tightening torques. Phillips drive is x-shaped for installation with a phillip screw driver.<br> The design is often criticized for its tendency to cam out at lower torque levels than other "cross head" designs.<br> There has long been a popular belief that this was actually a deliberate feature of the design, for the purpose of assembling aluminum aircraft without over tightening the fasteners.<br>