Screws and Sizing

Screws and Driver Bit Sizing

Screw SizeDriver Bit Size  
Screw Size MetricScrew Size GaugeSquare Driver Bit Size Dimension of Square Indent in the head of the Screw
2.9mm4g#1 Yellow2.0mm
3.5mm6g#1 Green2.5mm
3.9mm7g#1 Green2.5mm
4.2mm8g#2 Red3.0mm
4.8mm10g#2 Red3.0mm
5.5mm12g#3 Black3.50mm