The TNA® System
Torque + Angle TNA® is the only fastening system that delivers both a quantifiable Snug Tight condition – ensuring every bolt in a connection meets a minimum requirement for tension – and the precise required angle for the perfect final pretension. No other system or method can match the TNA® Torque + Angle Fastening System for producing the highest level of accuracy and reliability in both the snug and final tensioning processes.
ASTM F3148 Specification
144ksi Fixed Spline Bolt Assemblies
For application using the Torque + Angle Installation Method. This revolutionary structural bolt grade is designed to allow for a single bolt grade to be used in all connection types.