SAE AIR 1471A

SAE AIR 1471A

One of the most technically challenging tasks in the precision engineering and aerospace assembly process is to develop a clamp load that is consistent and predictable when you tighten threaded fasteners. Friction conditions that vary according to surface geometry, lubrication, coating, and the type of tool are used to control the relationship between torque applied and torque-generated clamp force. SAE AIR 1471A provides the aerospace and engineering community with recommended practices for torque tightening procedures, clamp load management, and fastener assembly quality control. Presto Stantest's torque testing machines deliver the measurement accuracy and tightening analysis capability that SAE AIR 1471A-compliant fastener evaluation requires. 

Significance

Improperly torquing aerospace assemblies, either under or over, can have a direct effect on the integrity and fatigue life, and thus flight safety. SAE AIR 1471A provides a consensus-driven vehicle for manufacturers, assembly engineers, and maintenance organizations to develop technically based reference criteria for torque specifications for aerodynamic and industrial safety-critical fastenings, choose proper tightening methods for fastener assemblies, and account for scatter in friction effects, as well as validation of assembly processes to meet desired clamp loads.

Scope

SAE AIR 1471A includes recommended practices for the tightening of threaded fasteners in areas on an airplane, in the powerplant, or in precision engineering devices where joint preload is to be verified and repeated, including clamp load behavior, friction coefficient considerations, and methods of torque control.