Socket set screws NAAMS are set to ANSI B18.3.6 dimensional specifications and made from class 45H steel. The hexagon socket size starts at 2.5 and goes up to 12 and nominal screw lengths range from 3 to 30. They come in three different styles. The F21 series has a flat point while F22 series comes with a cone point and lastly the F23 series has a cup point.