#4 x 12.7mm \/ 1\/2" Button Head Sheet Metal Screws (8 Pack) from Du-Bro - 527
This design is by far the best way to mount servos, cowls, landing gear, etc. The wide\/low profile head of the screw acts as a washer and they also have a socket head for easy, no slip installation. Bright Zinc plated with clear chromate.