SAE J174M

SAE J174M

For reliable bolted joint performance in metric fastener applications, it is important to accurately characterize the relationship between the applied tightening torque and the clamp force generated inside the bolted joint. However, this relationship is affected by surface coatings, thread condition, lubrication, and the geometry of the bearing surfaces, for which reason a standardized laboratory measurement is essential to assist in making informed assembly engineering decisions. SAE J174M establishes the metric counterpart to SAE J174, providing a standardized torque-tension test procedure specifically developed for metric steel threaded fasteners. Presto Stantest's torque and clamp force testing machines, with integrated simultaneous torque and axial load measurement, are fully suited to SAE J174M-compliant metric fastener characterization.

Significance

SAE J174M provides automotive, aerospace, and industrial fastener manufacturers, assembly engineers, and surface treatment suppliers with a repeatable, objective test methodology for quantifying torque coefficient, friction coefficient, and clamp load generation in metric fastener systems — enabling accurate torque specification development, coating and lubricant comparative evaluation, supplier qualification, and production assembly process validation across safety-critical and performance-driven bolted joint applications.

Scope

SAE J174M covers apparatus requirements, test specimen specifications, lubrication and surface condition documentation, testing procedure, and calculation methods for determining torque-tension characteristics of metric steel threaded fasteners under controlled laboratory tightening conditions across the full range of metric thread sizes used in automotive and engineering assemblies.