ASTM F2437

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 four grades.

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 40,250 –44,450 73,150 – 80,900 23.950 – 26,450 47,300 – 52,300
1-1/4 51,100 – 56,450 91,750 – 101,450 30,400 – 33,600 59,850 – 66,150
1-3/8 61,150 – 67,600 112,450 – 124,250 38,550 – 42,600 73,800 – 81,600
1-1/2 74,350 – 82,150 135,150 – 149,400 44,050 – 48,700 89,300 – 98,700
1-3/4 74,450 – 82,300 177,850 – 196,500 59,550 – 65,850 124,600 – 137,750
2 98,000 – 108,300 236,850 – 261,750 78,650 – 86,950 165,800 – 183,300
2-1/4 127,400 – 140,800 277,900 – 307,100 102,050 – 112,750 212,900 – 235,350
2-1/2 156,750 – 173,250 379,600 – 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%