Fastener Fact

Key values for your construction!

In the construction sector, it is crucial to inform clients about the distinction between the pull-out and shear values. This difference can be unclear to some clients, but it is an essential part of the construction process. The pull-out value is particularly important as it determines how many screws are needed for each construction project. This value is especially relevant in large new construction projects and is also necessary for approval by structural engineers. Understanding this difference enables clients to make informed decisions and contributes to the successful and safe execution of construction projects.

Pull-out value: The pull-out value of a fastener tells us how much tensile force it can withstand before it loosens from the substrate. This describes how well it remains securely attached when pulled. Each substrate has its own pull-out value, so it's important to choose the right fastener for the correct substrate or backing structure to ensure the screw remains firmly in place.

Pull-through value: The pull-through value tells us how much force a fastener can withstand under tensile load. This indicates how well the fastener prevents the material from pulling through over the head of the fastener. Resistance to pull-through is determined by the design of the fastener head, with the size of the flange playing a crucial role, along with the diameter of the washer and the thickness of the material being fastened.

Shear value: The shear value tells us how well a fastener resists lateral forces. When the fastener is subjected to lateral forces, the connection may fail. This can occur within the fastener itself or between the substrate/backing structure and the material being fastened to it. Shear resistance is especially important in roofing and facade systems, which experience structural lateral forces.