Using a Tension Measuring Device Contents: Section 1 Overview...2 Section 2 Definitions...3 Section 3 Apparatus...4 Section 4 Part I, Rotational Capacity Testing...5 Section 5 Part II, Values for Fasteners with ASTM A 490 Bolts...8 Section 6 Identification...9 Texas Department of Transportation 1 TxDOT 08/1999
Section 1 Overview Section 1 Overview This method covers the procedure for performing rotational capacity testing of fasteners with ASTM A 325 and A 490. The values shown in the tables of 'Part I, Rotational Capacity Testing' apply to fastener assemblies with ASTM A 325 bolts. The values shown in the tables of 'Part II, Values for Fasteners with ASTM 490 Bolts' address fasteners with ASTM A 490 bolts. Units of Measurement The values given in parentheses (if provided) are not standard and may not be exact mathematical conversions. Use each system of units separately. Combining values from the two systems may result in nonconformance with the standard. Texas Department of Transportation 2 TxDOT 08/1999
Section 2 Definitions Section 2 Definitions The following terms and definitions are referenced in this test method: Bolt length - Bolt length is the distance from the end of the threaded shank to the underside of the bolt head. (See 'Bolt Diagram') Grip length - Grip length is the region between the bearing face of a nut and the bolt head. (See 'Bolt Diagram') Long bolts - Long bolts are bolts that will fit in a direct tension indicator with the required "stick-out." Short bolts - Short bolts are bolts that are too short to be assembled in a direct tension indicator. These bolts may be tested in a steel plate, web, or flange, which contains a hole of the required diameter. Figure 1. Bolt Diagram. Texas Department of Transportation 3 TxDOT 08/1999
Section 3 Apparatus Section 3 Apparatus The following apparatus is required: Torque wrench, calibrated, capable of measuring the torque values listed in Step 6 of the 'Rotational Capacity of Long Bolts' procedure Tension measuring device (i.e. Skidmore-Wilhelm or equivalent), calibrated, of size required for bolts to be tested Spacers and/or washers, with hole sizes no larger than 1.6 mm (1/16 in.) greater than bolt to be tested Steel section, on which to mount the bolt calibrator. Flange of girder or cross frame accessible from the ground is satisfactory Steel section, with hole to install bolt. See the 'Rotational Capacity of Short Bolts' procedure for requirements Spud wrench, or equivalent. Texas Department of Transportation 4 TxDOT 08/1999
Section 4 Part I, Rotational Capacity Testing Section 4 Part I, Rotational Capacity Testing This part describes the procedure for performing rotational capacity testing of fasteners. The values shown in the tables apply to fastener assemblies with ASTM A 325 bolts. Procedure Long Bolts The following table describes steps used in rotational capacity testing of long bolts. Rotational Capacity of Long Bolts Step Action 1 Attach the tension-measuring device to a convenient steel section. 2 Measure and record the bolt length (see 'Bolt Diagram'). 3 Thread the nut on the bolt, and measure and record the stick out of the bolt when 3 to 5 full threads of the bolt are located within the grip length (see 'Bolt Diagram' ). 4 Mark off a vertical line, plus lines at 1/3 of a turn (120 ) and 2/3 of a turn (240 ), measured in a clockwise direction, from vertical on the face plate of the tension measuring device. 5 Install the bolt into the tension-measuring device. Include the required number of shim plates and/or washers (always use at least one washer under the nut) to produce the stick out measured in Step 3. 6 Using a spud wrench or equivalent, tighten the bolt to the snug tension listed below and to within a tolerance of -0, +9 kn ( -0, +2 kips). Snug tension will be indicated on the tension indicator. (Refer to 'Table 1, Values for Fasteners with ASTM A 490 Bolts' table.) U. S. BOLTS (A 325) Bolt 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 (In.) Snug Tension (kips) 1 2 3 4 5 6 7 9 10 S. I. BOLTS (A 325) Bolt 16 20 22 24 27 30 36 (mm) Snug Tension (kn) 9 14 18 21 27 33 47 7 Match mark the nut at the vertical line marked in Step 4 on the faceplate of the tensionmeasuring device. 8 Using the calibrated manual torque wrench, tighten the bolt to at least the tension listed below. Record the torque required to reach the tension and the value of the corresponding bolt tension. Torque must be measured with the nut in motion. (Refer to 'Table 2, Values for Fasteners with ASTM A 490 Bolts' table.) U. S. BOLTS (A 325) Bolt 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 (in.) Tension (kips) 12 19 28 39 51 56 71 85 103 S. I. BOLTS (A 325) Bolt 16 20 22 24 27 30 36 Texas Department of Transportation 5 TxDOT 08/1999
Section 4 Part I, Rotational Capacity Testing Rotational Capacity of Long Bolts Step Action (mm) Tension (kn) 91 142 176 205 267 326 475 9 Further tighten the bolt to the rotation listed below. The rotation is measured from the initial marking in Step 7. Record the bolt tension after achieving this rotation. Assemblies which fail prior to this rotation either by stripping of the threads or fracture of the bolt fail the test. 10 The bolt tension measured in Step 9, after the required rotation, must equal or exceed the values in the table shown below. Assemblies which do not meet this tension have failed the test. (Refer to the 'Table 3, Values of Fasteners with ASTM A 490 Bolts' table.) Bolt Length (measured in Step 2) Required Rotation (turns) 4 x Bolt or Less Greater than 4 but no more than 8 x Bolt 2/3 1 1-1/3 Greater than 8 x Bolt U. S. BOLTS (A 325) Bolt 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 (in.) Tension (kips) 14 22 32 45 59 64 82 98 118 S. I. BOLTS (A 325) Bolt 16 20 22 24 27 30 36 (mm) Tension (kn) 105 163 202 236 307 375 546 11 Loosen and remove the nut; examine the threads on the nut and bolt. No signs of thread shear failure, stripping, or torsional failure of the bolt should be evident. Assemblies that have evidence of stripping have failed the test. (Elongation of the bolt, in the threads between the nut and bolt head, is to be expected at the required rotation and is not to be classified as a failure). 12 Calculate and record the torque value as shown under 'Calculations.' Short Bolts The following table describes the steps used in rotational capacity testing of short bolts: Rotational Capacity of Short Bolts Step Action 1 Measure and record the bolt length (see 'Bolt Diagram' ). Install the nut on the bolt and measure the stick out of the bolt when 3 to 5 full threads of the bolt are located within the grip length (see 'Bolt Diagram'). 2 Mark a vertical line and lines 1/3 of a turn (120 ), 1/2 turn (180 ), and 2/3 of a turn (240 ), measured in a clockwise direction, from vertical on the plane of the plate, web, or flange. 3 Install bolt into hole of steel plate, web, or flange with required number of shim plates and/or washers (at least one washer under nut must always be used) to produce thread stick out in Step 1. 4 Snug the bolt using a spud wrench. Snug condition should be the normal effort applied to a 305 mm (12 in.) long wrench. The applied torque should not exceed 20% of the torque shown in Step 6. Match mark the nut at the vertical line marked in Step 2 on the plate, web, or flange. 5 Tighten the bolt by turning the nut using the torque wrench to the rotation listed below. A second wrench must be used to prevent rotation of the bolt head during tightening. Record the torque required to reach this rotation. The torque must be measured with the nut in motion. Texas Department of Transportation 6 TxDOT 08/1999
Section 4 Part I, Rotational Capacity Testing Bolt Length (measured in Step 1) 4 x Bolt or Less Greater than 4 but no more than 8 x Bolt Greater than 8 x Bolt Required Rotation (turns) 1/3 1/2 2/3 6 The measured torque should not exceed the values listed below. Assemblies that exceed the listed torques have failed the test. (Refer to 'Table 4, Values for Fasteners with ASTM A 490 Bolts' table.) U.S. BOLTS (A 325) Bolt (in.) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Torque (ft.-lbs) 150 290 500 820 1230 1500 2140 2810 3690 S. I. BOLTS (A 325) Bolt 16 20 22 24 27 30 36 (mm) Torque(N-m) 419 817 1111 1415 2070 2813 4912 7 Tighten the bolt further to the rotation required below. The rotation is measured from the initial marking in Step 4. Assemblies, which fail prior to this rotation either by stripping of the threads or fracture of the bolt, fail the test. Bolt Length (measured in Step 1) Required Rotation (turns) 4 x Bolt or Less Greater than 4 but not more than 8 x Bolt 2/3 1 1-1/3 Greater than 8 x Bolt 8 Loosen and remove the nut; examine the threads on the nut and bolt. No signs of thread shear failure, stripping, or torsional failure of the bolt should be evident. Assemblies that have evidence of stripping have failed the test. (Elongation of the bolt, in the threads between the nut and the bolt head, is to be expected at the required rotation and is not to be classified as a failure.) Calculation The following calculation determines the torque value: Torque 025. P D Where: Torque = torque, N-M (ft.-lbs.) measured with the calibrated torque wrench and recorded in Step 8. P = measured bolt tension, in N (lbs.) from the direct tension indicator and recorded in Step 8. D = bolt diameter, in m (ft.) (diameter in m = mm/1000; diameter in feet = diameter in inches/12). The torque measured and recorded in Step 8 must be equal to or less than this calculated value. Assemblies with torque values exceeding this calculated value fail the test. Texas Department of Transportation 7 TxDOT 08/1999
Section 5 Part II, Values for Fasteners with ASTM A 490 Bolts Section 5 Part II, Values for Fasteners with ASTM A 490 Bolts This part covers values to use when performing rotational capacity testing of fasteners with ASTM A 490 bolts. Table 1 (Refer to Step 6 of 'Rotational Capacity of Long Bolts' procedure) Table 1, Values for Fasteners with ASTM A 490 Bolts U. S. BOLTS (A 490) Bolt (in.) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Snug Tension (kips) 2 3 4 6 7 9 12 15 17 S. I. BOLTS (A 490) Bolt (mm) 16 20 22 24 27 30 36 Tension (kn) 11 18 22 26 33 41 60 Table 2 (refer to Step 8 of the 'Rotational Capacity of Long Bolts' procedure) Table 2, Values for Fasteners with ASTM A 490 Bolts U.S. BOLTS (A 490) Bolt (in.) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Tenison (kips) 15 24 35 49 64 80 102 121 148 S.I. BOLTS (A 490) Bolt (mm) 16 20 22 24 27 30 36 Tension (kn) 114 179 221 257 334 408 595 Table 3 (refer to Step 10 of the Rotational Capacity of Long Bolts' procedure) Table 3, Values for Fasteners with ASTM A 490 Bolts U. S. BOLTS (A 490) Bolt (in.) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Tension (kips) 17 28 40 56 74 92 117 139 170 S. I. BOLTS (A490) Bolt (mm) 16 20 22 24 27 30 36 Tension (kn) 131 205 254 295 384 469 684 Table 4 (refer to Step 6 of the 'Rotational Capacity of Short Bolts' procedure) Table 4, Values for Fasteners with ASTM A 490 Bolts U. S. BOLTS (A 490) Bolt (in.) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Torque (Ft.-Lbs.) 200 400 720 1150 1710 2530 3590 4870 6280 S. I. BOLTS (A 490) Bolt (mm) 16 20 22 24 27 30 36 Torque (N-M) 525 1026 1395 1773 2592 3520 6158 Texas Department of Transportation 8 TxDOT 08/1999
Section 6 Identification Section 6 Identification A rotational-capacity lot number should be assigned to each combination of fastener assemblies tested. Texas Department of Transportation 9 TxDOT 08/1999