1.1 This specification covers the requirements for carbon and alloy steel compressible-washer-type direct tension indicators capable of indicating a specified bolt tension in cap screws, bolts, anchors, and studs.
1.3 There are two Types of DTIs covered by this specification, Type 1 and Type 2.
1.3.1 Type 1 DTIs are suitable for comparatively large bearing surfaces.2 Type 1 DTIs are available in Grades 55 and 105, which differ in the amount of tension they indicate at a prescribed gap (see Table 1).
| DTI | Mean Compression LoadB Range | Mean Compression LoadC Range | ||
| Grade 5 | Grade 8 | Grade 55 | Grade 105 | |
| 1/4 | 2200 to 2450 | 3100 to 3450 | .β.β. | .β.β. |
| 5/16 | 3500 to 3850 | 4950 to 5500 | .β.β. | .β.β. |
| 3/8 | 5300 to 5850 | 7500 to 8300 | .β.β. | .β.β. |
| 7/16 | 7200 to 7900 | 10β100 to 11β200 | .β.β. | .β.β. |
| 1/2 | 9700 to 10β700 | 13β700 to 15β340 | 4450 to 4900 | 8500 to 9400 |
| 9/16 | 12β350 to 13β600 | 17β400 to 19β200 | 5700 to 6300 | 10β900 to 12β050 |
| 5/8 | 15β550 to 17β200 | 21β850 to 24β200 | 7050 to 7800 | 13β500 to 15β000 |
| 3/4 | 22β600 to 25β000 | 31β900 to 35β300 | 10β500 to 11β600 | 20β000 to 22β150 |
| 7/8 | 30β850 to 34β100 | 43β550 to 48β100 | 14β500 to 16β000 | 27β650 to 30β550 |
| 1 | 40β200 to 44β400 | 56β700 to 62β700 | 19β000 to 21β000 | 36β250 to 40β100 |
| 11/8 | 45,β100 to 49β850 | 73β150 to 80β900 | 23β950 to 26β450 | 47β300 to 52β300 |
| 11/4 | 56β550 to 62β550 | 91β750 to 101β450 | 30β400 to 33β600 | 59β850 to 66β150 |
| 13/8 | 69β350 to 79β750 | 112β450 to 124β250 | 38β550 to 42β600 | 73β800 to 81β600 |
| 11/2 | 83β350 to 92β150 | 135β150 to 149β400 | 44β050 to 48β700 | 89β300 to 98β700 |
| 15/8 | .β.β. | .β.β. | 55β800 to 61β700 | 106β200 to 117β400 |
| 13/4 | 121β850 to 134β650 | 177β850 to 196β500 | 59β550 to 65β850 | 124β600 to 137β750 |
| 17/8 | 154β550 to 170β800 | 206β050 to 227β750 | 75β550 to 83β500 | 144β500 to 159β700 |
| 2 | 160β050 to 177β200 | 236β850 to 261β750 | 78 650 to 86 950 | 165β800 to 183β300 |
| 21/4 | 208β400 to 230β350 | 277β900 to 307β100 | 102β050 to 112β750 | 212β900 to 235β350 |
| 21/2 | 256β500 to 283β500 | 379β600 to 419β600 | 125β400 to 138β600 | 240β550 to 265β850 |
1.4 Direct tension indicators are intended for installation under a bolt or cap screw head, a hex nut, or against a hardened washer or other flat hardened surface.
1.5 The following precautionary statement pertains only to the test method portions, Section 12 and Appendix XI of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
This specification covers the requirements for carbon and alloy steel compressible-washer-type direct tension indicators (DTIs) capable of indicating a specified bolt tension in cap screws, bolts, anchors, and studs. These DTIs are intended for installation under a bolt or cap screw head, a hex nut, or against a hardened washer or other flat hardened surface. The following are two types of DTIs: Type 1 DTIs are suitable for comparatively large bearing surfaces and Type 2 DTIs are suitable for comparatively smaller bearing surfaces. DTIs shall have a configuration produced by extrusion, punching, pressing, or similar forming to permit a measurable decrease in thickness when placed in compression. The design shall be such that the degree of plastic deformation of the protrusions shall indicate the tension in a tightened cap screw, bolt, anchor, or stud. The process used for heat treatment of DTIs, if required, shall be through-hardening by heating to a temperature above the upper transformation temperature, quenching in oil, and then tempering by reheating to a suitable temperature to attain desired mechanical/performance properties. Protective coatings, platings, or finishes may be applied on the DTIs if specified. Compression load and hardness of the DTIs shall be determined by performing mechanical tests.
| SDO | ASTM: ASTM International |
| Document Number | F2437 |
| Publication Date | April 1, 2012 |
| Language | en - English |
| Page Count | 6 |
| Revision Level | 12 |
| Supercedes | |
| Committee | F16.02 |