New Jersey

Department of Transportation

Standard Specifications

for Road and Bridge Construction

2007


NJDOT S-2 Rotational-Capacity Test on Bolts Too Short
to Fit Tension Calibrator

  1. Scope. This test method is used for determination of high-strength steel bolt assembly acceptance for rotational capacity for bolt assemblies that are too short to fit in a tension calibrator. Use NJDOT S-1 for bolts that are long enough to fit in the tension calibrator.

  2. Apparatus. Use the following apparatus:

    1. Calibrated torque wrench and spud wrench or equivalent.
    2. Spacers and/or washers with hole-size no larger than 1/16 inch greater than bolt to be tested.
    3. Steel section with normal size hole to install bolt. Any available splice hole can be used with a plate thickness that will provide the number of threads under the nut required in Step 1 of the procedure.

  3. Procedure. Perform the following steps:

    1. Before testing, verify that the bolt is too short for testing as specified in NJDOT S-1.
    2. Mark on the first 3 to 5 threads that are located closest to the bolt head.
    3. Insert the bolt into the steel section using shim plates or washers under the bolt head, as needed, to ensure that the 3 to 5 threads that were marked in Step 2 are just visible from the opposite side. Assemble a washer and nut onto the bolt up to the marked threads. Use a rotational capacity washer from the same rotational-capacity lot as the bolt and nut. If a washer is not required for the installation, use an ASTM F 436 washer of the proper diameter for the test.
    4. Snug the bolt using a hand wrench. Do not exceed 20 percent of the torque determined in Step 6.
    5. Match mark a corner of the nut and the plate.
    6. Using the torque wrench, tighten the nut to the rotation listed in Table S-2-1. Use a second wrench to prevent rotation of the bolt head during tightening. Record the torque required to reach this rotation. Measure and record the torque required to reach the rotation with the nut in motion.


    7. Table S-2-1 Required Initial Rotation
      Rotation Bolt Length
      120 degrees (1/3 turn) ≤ 4 diameters
      180 degrees (1/2 turn) > 4 diameters and ≤ 8 diameters
      240 degrees (2/3 turn) > 8 diameters

    8. If the measured torque exceeds the values listed in Table S-2-2, the assembly fails the test.


    9. Table S-2-2 Maximum Torque Requirements
      Bolt Size 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2
      Maximum Torque, ft-lbs 150 290 500 820 1230 1500 2140 2810 3690

    10. Tighten the bolt further to the rotation required in Table S-2-3. Measure the rotation from the initial marking in Step 5. Assemblies that fail before this rotation either by stripping or fracture fail the test.


    11. Table S-2-3 Final Initial Rotation
      Rotation Bolt Length
      240 degrees (2/3 turn) ≤ 4 diameters
      360 degrees (1 turn) > 4 diameters and ≤ 8 diameters
      480 degrees (1-1/3 turns) > 8 diameters

    12. Loosen the assembly and remove nut to examine the threads on the nut and bolt. Check for signs of thread shear failure, stripping, or torsional failure of the nut and bolt. Assemblies that have evidence of thread shear failure, stripping, or torsional failure fail the test.

  4. Report. Report the following:

    1. Size, manufacturer and lot number for the bolt assembly.
    2. Measured torque at the initial rotation.
    3. Observations of the thread condition.
    4. Pass/Fail status of the bolt assembly.

Last Document Correction:
December 14, 2007