How to calculate the load per screw on decking
Fasteners are a vital component to ensure the safe installation of structural decks or trays. The correct fixing, to be specified by the fastener manufacturer, to suit the application of fixing to cold rolled thin gauge purlins, hot rolled steel sections or timber supports. Self drilling/self tapping screws (commonly known as drill screws), must be a minimum 5.5mm diameter, available in carbon steel or austenitic stainless steel, and must resist all pullout, pullover and shear forces.
The load acting on a screw can be calculated thus:-
Screw Load (kN) = Wind Load (kN/m2) x Support Centers (m) x Screw Centers (m) x Factor of Safety
Example:- To find the fastener load for D60 deck spanning 3000mm with an applied wind load of 1.5kN/m2
Screw Load = 1.5 x 3 x 0.2 x 2 = 1.8kN
Fastener manufacturers can confirm:-
Pullout, pullover and shear values, to suit gauge of deck / tray, type and thickness of support structure, and provide information on the correct torque setting for screw guns, to ensure that the screw is not over-driven or under-driven.
For further information please do not hesitate to get in touch with our Technical Department at Tata Steel, E mail: firstname.lastname@example.org