Torque + Angle Installation Method

  1. Set the tool to the Snug Mode and engage the first bolt in your connection.
  2. Pull and hold the trigger until the tool shuts off.
  3. If the cycle was completed successfully the Cycle Indicator Light will show solid green.
  4. Repeat the process for each bolt in the connection.

For larger connections, a second snug pass can be performed to ensure all plies are in firm contact and that all the bolts are snug to the same value. For connections only requiring a snug condition your work is done. For Pre-Tensioned or Slip-Critical Connections, proceed to Step 2.

After the Snug Tightening step is completed:

  1. Switch the tool to the Angle Mode
  2. Set the Angle Control Dial to the degree of rotation specified for your bolt length in ASTM F3148 (It’s 90º or 120º)
  3. Engage the first bolt in the pattern that you established during the snug mode. Pull and hold the trigger until the tool shuts off.
  4. If the cycle was completed successfully the Cycle Indicator Light will show solid green.
  5. Repeat the process for each bolt in the connection.

Your bolts are now installed to a consistently reliable tension well above the specified minimum.

Inspection after Snug Tightening

  1. Perform routine observation of the snug tightening process to verify proper techniques are followed as described in Step 1: Snug Tightening
  2. Verify that the plies in the connection are in firm contact.
  3. Verify that the proper bolt length was used. The face of the nut shall be at least flush with the first thread of the bolt and there should be no more than 3 threads stick-out beyond the face of the nut to prevent thread runout.

Inspection after Angle Tightening

  1. Perform routine observation of the final angle tightening process to verify proper techniques are followed as described in Step 2: Angle Tightening

NOTE: If routine observation is not possible, match marking for final installation may be required during the angle tightening process. This step of visual inspection should be included in the scope of work or contract documents to avoid disputes.

ASTM F3148-17a Standard Specification for High Strength Structural Bolt Assemblies, Steel and Alloy Steel, Heat Treated, 144ksi Minimum Tensile Strength, Inch Dimensions.

Within the standard you will find all of the information required to specify TNA®.  Included in the standard you will also find important additional information needed to implement the system.  In F3148 you will find Annex A1. Rotational Capacity (RC) Tests, Appendixes X1. Test and Installation Procedures for Torque-and-Angle Tensioning of Fixed Spline F3148 Assemblies, X2. Pre-Installation Verification Testing and X3. Installation Procedure.  In these Appendixes are the required Pre-Installation Verification Testing Procedure and the formal Installation Procedure.  This information is typically found in RCSC ” Specification for Structural Joints Using High-Strength Bolts”.  During the interim period prior to publication by RCSC these procedures will be referenced in this ASTM document.  When the Torque-and-Angle installation method can be included in the RCSC publication, it will be balloted for removal from the ASTM document.  This form of reference has precedence from other bolting innovations following the same acceptance path.

To obtain your own copy of F3148 you can go to www.astm.org.  For subscribers, the new standard can be downloaded as part of your subscription service.  If you’re not a subscriber, download your own copy from the ASTM site or contact LeJeune Bolt and we will provide a serialized copy free of charge.