Purlin bolts and nuts have preformed washers and are used for fixing purlins.
Thread pitch = 1.75mm
Hexagon head Across the Flats ( AF ) = 18mm
Flange Diametre = 28mm
Head Height = 10.5mm
Nut Height = 12.5mm
Mildsteel Class 4.6
Zincplated Finish
