In Pre-Engineered Building (PEB) erection, every component has a specific role in maintaining the strength, stability, and performance of the structure. While major structural members such as columns, rafters, purlins, and bracings receive significant attention, the fasteners and bolted connections joining these components are equally important.
One of the most critical aspects of installing structural fasteners is achieving the specified torque value.
Torque is the rotational force applied to a bolt or nut during tightening. Applying the correct torque helps develop the required bolt tension and ensures that the connection performs as intended.
A fastener that is under-tightened or over-tightened can compromise the connection and potentially affect the long-term reliability of the PEB structure.
What Is Torque in Fastener Installation?
Torque is the twisting force used to tighten a nut or bolt. It is commonly measured in N·m (Newton-metres) or other specified units depending on the project and applicable standards.
When torque is applied to a fastener, most of the applied torque is associated with overcoming friction in the threads and under the nut/bolt head. Only a portion contributes directly to bolt tension.
This means that achieving a specified torque is not simply about "tightening the bolt as much as possible." The correct tightening procedure, fastener condition, lubrication, washer arrangement, and installation method all matter.