Scope
ASTM F2437 covers the requirements for compressible washer type direct tension indicators in diameters ranging from 1/4” to 2-1/2” inclusive. These washers are capable of indicating a specified bolt tension in cap screws, bolts, anchors, and studs. They are available in two types, and two grades within each type.
F2437 Types and Recommended Fasteners
Type/Grade | Cap Screw, Bolt, Anchor, or Stud | Hex or Heavy Hex Nut | Flat Washer |
Type 1, Grade 55 | F1554G55 or A307 | A194-2H/A563 Gr.A/C/DH | F436 |
Type 1, Grade 105 | A193 B7 or F1554G105 | A194-2H / A563 DH | F436 |
Type 2, Grade 5 | A449/A354 Gr.BC or SAE J429 Gr.5 | A563 Gr. B/C/D/DH or SAE J995 Gr.5 | F436 |
Type 2, Grade 8 | A354 BD or SAE J429 Gr.8 | A563 Gr.D/DH or SAE J995 Gr.8 | F436 |
F2437 Acceptable Compression Load Range
Mean Compression Load Range (lbs) | ||||
Diameter | Grade 5 | Grade 8 | Grade 55 | Grade 105 |
½ | 9,700 – 10,700 | 13,700 – 15,340 | 4,450 – 4,900 | 8,500 – 9,400 |
5/8 | 15,550 – 17,200 | 21,850 – 24,200 | 7,050 – 7,800 | 13,500 – 15,000 |
¾ | 22,600 – 25,000 | 31,900 – 35,300 | 10,500 – 11,600 | 20,000 – 22,150 |
7/8 | 30,850 – 34,100 | 43,550 – 48,100 | 14,500 – 16,000 | 27,650 – 30,550 |
1 | 40,200 – 44,400 | 56,700 – 62,700 | 19,000 – 21,000 | 36,250 – 40,100 |
1-1/8 | 45,100 – 49,850 | 73,150 – 80,900 | 23.950 – 26,450 | 47,300 – 52,300 |
1-1/4 | 56,550 – 62,550 | 91,750 – 101,450 | 30,400 – 33,600 | 59,850 – 66,150 |
1-3/8 | 69,350 – 79,750 | 112,450 – 124,250 | 38,550 – 42,600 | 73,800 – 81,600 |
1-1/2 | 83,350 – 92,150 | 135,150 – 149,400 | 44,050 – 48,700 | 89,300 – 98,700 |
1-3/4 | 121,850 – 134,650 | 177,850 – 196,500 | 59,550 – 65,850 | 124,600 – 137,750 |
2 | 160,050 – 177,200 | 236,850 – 261,750 | 113,000 – 124,300 | 165,800 – 183,300 |
2-1/4 | 208,400 – 230,350 | 277,900 – 307,100 | 102,050 – 112,750 | 212,900 – 235,350 |
2-1/2 | 256,500 – 283,500 | 379,600 – 419,600 | 125,400 – 138,600 | 240,550 – 265,850 |
The user is not obliged to install fasteners and DTIs to these tensions, and is free to specify installation to lower tension values. When so specified the DTI supplier shall provide a load-gap curve to enable the user to select the appropriate gap criteria for the intended target tension for the application. | ||||
F2437 Chemical Requirements, Heat Analysis
Element | Heat Analysis, All Types and Grades |
Carbon | 0.30 – 0.50% |
Manganese | 0.50 – 0.90% |
Phosphorus | 0.035% max |
Sulfur | 0.040% max |
Silicon | 0.15 – 0.35% |