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ASTM F2437/2437M Direct tension Washers Specification

Carbon and Alloy Steel Direct Tension Washers for use with Cap Screws, Bolts, Anchors, and Studs

Related Specifications of ASTM F2437/ F2437 Bolting

A193 A194 A307 A354 A449 A563

ASTM F2437/F2437M Recommended Fasteners

Series/Grade or Property Class Recommended Cap Screws, Bolts, Anchors, or StudsA Recommended NutsB Recommended Flat Washers
Inch Fasteners Style 2 Grade 55 Specification F1554 Grade 55 Specification A307 Specification A194/A194M2H Specification A563 A, C, DH Specification F436/F436M
Style 2 Grade 105 Specification A193/A193M B7 Specification F1554 Grade 105 Specification A194/A194M2H Specification A563 DH Specification F436/F436M
Style 1 Grade 5 Specification A449, Specification A354 BC SAE J429 Grade 5 SAE J995 Grade 5 Specification A563 B, C, D, DH Specification F436/F436M
Style 1 Grade 8 Specification A354 BD SAE J429 Grade 8 SAE J995 Grade 8 Specification A563 D, DH Specification F436/F436M
Metric Fasteners Property Class 8.8 Specification ISO 898-1 Class 8.8 Specification ISO 898-2 Class 10 Specification ISO 887 (300 HV) DIN 125 Part 2
Property Class 10.9 Specification ISO 898-1 Class 10.9 Specification ISO 898-2 Class 10 Specification ISO 887 (300 HV) ISO 7089
  • A) A Inch bolt and cap screw dimensions are designated in ASME B18.2.1 and metric bolt dimensions are designated in ISO 4014.
  • (B) Inch nuts dimensions are designated in ASME B18.2.2 and metric nut dimensions are designated in ISO 4032.

ASTM F2437/ F2437 Chemical Composition

Element Composition, %
Heat Analysis Product Analysis
C 0.30 to 0.55 0.27 to 0.58
Mn 0.50 to 0.90 0.47 to 0.93
P, max 0.04 0.048
S, max 0.045 0.053
Si 0.15 to 0.35 0.13 to 0.37
  • (A) Steel is considered to be alloy by the American Iron and Steel Institute when the maximum of the range given for the content of alloying elements exceeds one or more of the following limits: manganese, 1.65 %; silicone, 0.60 %; copper, 0.60 %; or in which a definite range or definite maximum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels: aluminum, chromium up to 3.99 %, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium, or any other alloying elements added to obtain a desired alloying effect.
  • (B) Suitable materials for weathering steel DTIs include the chemistries for Type 3 products listed in Specification F436/F436M.

ASTM F2437/F2437M Mechanical Requirements

ASTM F2437 Acceptable Range of Compression LoadA (Inch DTIs)

DTI Nominal Diameter (in.) Mean Compression LoadB Range in Pounds (lbs) Style 1 Mean Compression LoadC Range in Pounds (lbs) Style 2
Grade 5 Grade 8 Grade 55 Grade 105
1/4 2200 to 2450 3100 to 3450 . . . . . .
5/16 3500 to 3850 4950 to 5500 . . . . . .
3/8 5300 to 5850 7500 to 8300 . . . . . .
7/16 7200 to 7900 10 100 to 11 200 . . . . . .
1/2 9700 to 10 700 13 700 to 15 340 4450 to 4900 8500 to 9400
9/16 12 350 to 13 600 17 400 to 19 200 5700 to 6300 10 900 to 12 050
5/8 15 550 to 17 200 21 850 to 24 200 7050 to 7800 13 500 to 15 000
3/4 22 600 to 25 000 31 900 to 35 300 10 500 to 11 600 20 000 to 22 150
7/8 30 850 to 34 100 43 550 to 48 100 14 500 to 16 000 27 650 to 30 550
1 40 200 to 44 400 56 700 to 62 700 19 000 to 21 000 36 250 to 40 100
11/8 40 250 to 44 450 73 150 to 80 900 23 950 to 26 450 47 300 to 52 300
11/4 51 100 to 56 450 91 750 to 101 450 30 400 to 33 600 59 850 to 66 150
13/8 61 150 to 67 600 112 450 to 124 250 38 550 to 42 600 73 800 to 81 600
11/2 74 350 to 82 150 135 150 to 149 400 44 050 to 48 700 89 300 to 98 700
15/8 . . . . . . 55 800 to 61 700 106 200 to 117 400
13/4 74 450 to 82 300 177 850 to 196 500 59 550 to 65 850 124 600 to 137 750
17/8 ... 206 050 to 227 750 75 550 to 83 500 144 500 to 159 700
2 98 000 to 108 300 236 850 to 261 750 78 650 to 86 950 165 800 to 183 300
21/4 127 400 to 140 800 277 900 to 307 100 102 050 to 112 750 212 900 to 235 350
21/2 156 750 to 173 250 379 600 to 419 600 125 400 to 138 600 240 550 to 265 850
  • (A) Compression load requirements establish the capability of the direct tension indicators to satisfy typical tension requirements for these grades. 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 in accordance with 15.2 to enable the user to select the appropriate gap criteria for the intended target tension of the application.
  • (B) The Mean compression load values for Grades 5 and 8 in nominal sizes up through 1-1/2 in are based upon 75% of the proof load for SAE J429 cap screws. For Grade 5 in nominal sizes over 1-1/2 in and up to 2-1/2 in inclusive, the mean compression load values are based on 75% of the proof load for ASTM A449. For grade 8 in nominal sizes over 1-1/2 in and up to 2-1/2 in inclusive, mean compression load values are based upon 75 % of the proof load for ASTM A354BD.
  • (C) Mean compression load values for Grades 55 and 105 are based upon 60 % of the yield strength for the matching fasteners on which they are used.

ASTM F2437M Acceptable Range of Compression LoadA (Metric DTIs)

Nominal Diameter (M) Mean Compression Load Range in kN
Property Class 8.8 Property Class 10.9
M6 8 to 9 12 to 13
M8 15 to 17 22 to 24
M10 24 to 27 35 to 38
M12 35 to 39 50 to 55
M14 48 to 53 68 to 75
M16 65 to 72 93 to 103
M18 82 to 91 114 to 125
M20 105 to 116 145 to 160
M22 130 to 143 179 to 198
M24 151 to 167 209 to 231
M27 196 to 217 271 to 300
M30 240 to 265 332 to 367
M33 297 to 328 410 to 454
M36 349 to 386 483 to 534
M39 417 to 461 577 to 638
M42 479 to 529 662 to 732
M45 560 to 619 775 to 856
M48 628 to 695 869 to 961
M52 752 to 832 1041 to 1150
M56 868 to 959 1200 to 1327
M60 1009 to 1115 1396 to 1543
M64 1146 to 1266 1585 to 1752
M68 1308 to 1446 1810 to 2000
M72 1479 to 1635 2046 to 2262
  • (A) The Mean compression load values for property classes 8.8 and 10.9 are based upon 75% of the proof load for ISO 898-1 Bolts/Stud/Screws.

ASTM F2437 Dimensions of Style 1 and Style 2 Inch Fastener Direct Tension IndicatorsA

DTI Size,
Nominal Diameter
(in.)B		 Style 1: Grade 5 and Grade 8 Style 2: Grade 55 and Grade 105
Inside
Diameter (ID),
in.		 Outside
 Diameter (OD),
in.		 Thickness,
in. (min.)		 Protrusion 
Bearing
 DiameterC 
(PBD)		 Inside 
Diameter (ID),
in.		 Outside
Diameter (OD),
in.		 Thickness 
in. (min.)		 Protrusion 
Bearing 
Diameter 
(PBD)
1/4 0.254 to 0.258 0.505 to 0.525 0.097 0.394 . . . . . . . . . . . .
5/16 0.317 to 0.321 0.650 to 0.670 0.097 0.450 . . . . . . . . . . . .
3/8 0.379 to 0.383 0.780 to 0.800 0.104 0.506 . . . . . . . . . . . .
7/16 0.443 to 0.448 0.898 to 0.918 0.104 0.563 . . . . . . . . . . . .
1/2 0.508 to 0.512 0.950 to 0.970 0.104 0.675 0.515 to 0.520 1.020 to 1.040 0.104 0.746
9/16 0.573 to 0.577 1.052 to 1.072 0.126 0.731 . . . . . . . . . . . .
5/8 0.635 to 0.639 1.204 to 1.224 0.126 0.844 0.640 to 0.645 1.240 to 1.260 0.126 0.956
3/4 0.760 to 0.764 1.474 to 1.494 0.142 1.012 0.765 to 0.770 1.450 to 1.470 0.126 1.077
7/8 0.885 to 0.889 1.630 to 1.650 0.158 1.181 0.890 to 0.895 1.670 to 1.690 0.142 1.294
1 1.010 to 1.014 1.846 to 1.866 0.158 1.350 1.020 to 1.025 1.890 to 1.910 0.142 1.441
11/8 1.135 to 1.139 2.063 to 2.083 0.158 1.512 1.150 to 1.155 2.100 to 2.120 0.142 1.574
11/4 1.260 to 1.264 2.305 to 2.325 0.158 1.688 1.275 to 1.280 2.320 to 2.340 0.142 1.800
13/8 1.388 to 1.392 2.565 to 2.585 0.193 1.856 1.400 to 1.405 2.540 to 2.560 0.142 1.902
11/2 1.525 to 1.529 2.798 to 2.818 0.193 2.025 1.525 to 1.530 2.750 to 2.770 0.142 2.071
15/8 . . . . . . . . . . . . 1.650 to 1.655 2.970 to 2.990 0.193 2.234
13/4 1.767 to 1.772 3.265 to 3.285 0.193 2.363 1.775 to 1.780 3.185 to 3.205 0.193 2.475
2 2.030 to 2.040 3.735 to 3.755 0.193 2.700 2.030 to 2.040 3.620 to 3.640 0.193 2.741
21/4 2.275 to 2.280 4.205 to 4.225 0.193 3.038 2.275 to 2.280 4.050 to 4.070 0.193 3.078
21/2 2.525 to 2.530 4.675 to 4.695 0.193 3.375 2.525 to 2.530 4.480 to 4.500 0.193 3.416
  • (A) Dimensions are as-formed, before coatings, platings, and so forth.
  • (B) Nominal direct tension indicator sizes are intended for use with fasteners of the same nominal diameter.
  • (C) PBD maximum based upon minimum bearing surface of ASME B18.2.1 hex cap screw minimum bearing surface.

ASTM F2437M Dimensions of Property Class 8.8 and 10.9 Metric Fastener Direct Tension IndicatorsA

DTI SizeB Inside Diameter (ID), mm Outside Diameter (OD), mm Thickness, mm (minimum) Protrusion Bearing DiameterC(PBD) mm (maximum)
M6 6.25-6.35 13.65-15.65 2.464 8.88
M8 8.25-8.35 16.98-18.98 2.464 11.63
M10 10.25-10.35 20.37-22.37 2.642 14.63
M12 12.25-12.35 24.23-26.23 2.642 16.63
M14 14.25-14.35 27.56-29.56 2.642 19.64
M16 16.25-16.35 30.95-32.95 3.200 22.49
M18 18.25-18.35 33.76-35.76 3.200 25.34
M20 20.25-20.35 37.15-39.15 3.607 28.19
M22 22.25-22.35 41.43-43.43 4.013 31.71
M24 24.35-24.45 43.69-45.69 4.013 33.61
M27 27.35-27.45 49.34-51.34 4.013 38.00
M30 30.35-30.45 54.99-56.99 4.013 42.75
M33 33.35-33.45 59.51-61.51 4.902 46.55
M36 36.35-36.45 64.83-66.83 4.902 51.11
M39 39.35-39.45 70.58-72.58 4.902 55.86
M42 42.35-42.45 75.44-77.44 4.902 59.95
M45 45.35-45.45 81.09-83.09 4.902 64.70
M48 48.35-48.45 86.74-88.74 4.902 69.45
M52 52.40-52.50 92.39-94.39 4.902 74.20
M56 56.40-56.50 97.70-99.70 4.902 78.66
M60 60.40-60.50 103.35-105.35 4.902 83.41
M64 64.40-64.50 109.00-111.00 4.902 88.16
M68 68.40-68.50 114.65-116.65 4.902 92.48
M72 75.40-75.50 120.30-122.30 4.902 97.92
  • (A) Dimensions are as-formed, before coatings, platings.
  • (B) Nominal direct tension indicator sizes are intended for use with fasteners of the same nominal diameter.
  • (C) PBD maximum is based upon minimum bearing surface of hex head screws in ISO 4014.

ASTM F2437/ F2437 Bolting Surface Treatment Specifications

ASTM F2437/ F2437 Bolting Components Marking

Product Shall be Marked with our manufacturing trade mark "TorqBolt" or "TB" along with the designated Grade.
Grade and manufacturer’s identification symbols shall be applied to one end of studs and to the heads of bolts and screws of all sizes. (If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer’s identification symbol marked on the other end.) For bolts and screws smaller than 1⁄4 in. [6 mm] in diameter and studs smaller than 3⁄8 in. [10 mm] in diameter and for 1⁄4 in. [6 mm] in diameter studs requiring more than a total of three symbols, the marking shall be a matter of agreement between the purchaser and the manufacturer.

ASME Dimensional Standards

ASTM F2437/ F2437 Bolting Certifications

  • EN 10204 3.1
  • EN 10204 3.2
  • PED 2014/68/EC
  • MERKBLATT AD 2000 W2/W7/W10
  • API 20 E BSL 1/ BSL 2
  • NACE MR 0175
  • NACE MR 0103

ASTM F2437/ F2437 Testing Standards

ASME Threading Specifications