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The TurnaSure DTI Standards and Certifications

Standards of TurnaSure Bolting Services

TurnaSure DTIs are currently manufactured to the following standards:
  • ASTM F959 and F959M for use on inch or metric A325 or A490 ASTM (American Standard Structural Fasteners).
  • CEN Standard prEN 14399-9 (replacing BS 7644) for use on CEN Standard Structural Fasteners in the European Union.
  • ASTM F 2437-06 for Carbon Steel Compressible-Washer-Type Direct Tension Indicators for use with Cap Screws, Bolts, Anchors, and Studs.
  • TurnaSure’s DTIs are also manufactured for use on DIN 6914 10.9 structural bolts and Japanese Standard JISB 1186-F10T High Strength Structural Bolts.

Tables of Grade, Sizes and Specifications of TurnaSure DTIs

DTIs for Inch Structural Bolts ASTM F959 Supplied in Plain, Coated (specify) and Type-3 Weathering
Size Grade Bumps Minimum Compression Load (KIPS) Outside Diameter (In) Inside Diameter (In)
1/2 325 4 12.0 1.167-1.187 0.523-0.527
5/8 325 4 19.0 1.355-1.375 0.654-0.658
3/4 325 5 28.0 1.605-1.625 0.786-0.790
7/8 325 5 39.0 1.855-1.875 0.917-0.921
1 325 6 51.0 1.980-2.000 1.048-1.052
1 1/8 325 6 56.0 2.230-2.250 1.179-1.183
1 1/4 325 7 71.0 2.480-2.500 1.311-1.315
1 3/8 325 7 85.0 2.730-2.750 1.442-1.446
1 1/2 325 8 103.0 2.980-3.000 1.573-1.577
3/4 490 6 35.0 1.730-1.750 0.786-0.790
7/8 490 6 49.0 1.980-2.000 0.917-0.921
1 490 7 64.0 2.230-2.250 1.048-1.052
1 1/8 490 7 80.0 2.480-2.500 1.179-1.183
1 1/4 490 8 102.0 2.730-2.750 1.311-1.315
1 3/8 490 8 121.0 2.980-3.000 1.442-1.446
1 1/2 490 9 148.0 3.230-3.250 1.573-1.577
* Now available in our NEW Offset Extrusion design for enhanced performance with the new expanded AISC bolt hole standards.
bolting service Direct Tension Indicators
DTIs for Metric Structural Bolts ASTM F959M Supplied in Plain, Coated (specify) and Type-3 Weathering
Size Grade Bumps Minimum Compression Load (kN) Outside Diameter (mm) Inside Diameter (mm)
M16 8.8 4 91.0 35.20-36.80 16.75-16.85
M20 8.8 5 142.0 44.00-46.00 20.95-21.05
M22 8.8 5 176.0 48.40-50.60 23.05-23.15
M24 8.8 6 204.0 52.80-55.20 25.15-25.25
M27 8.8 6 267.0 59.40-62.10 28.30-28.40
M30 8.8 7 326.0 66.00-69.00 31.45-31.55
M36 8.8 8 475.0 79.20-82.80 37.75-37.85
M16 10.9 4 114.0 35.20-36.80 16.75-16.85
M20 10.9 6 179.0 44.00-46.00 20.95-21.05
M22 10.9 6 221.0 48.40-50.60 23.05-23.15
M24 10.9 7 257.0 52.80-55.20 25.15-25.25
M27 10.9 7 334.0 59.40-62.10 28.30-28.40
M30 10.9 8 408.0 66.00-69.00 31.45-31.55
M36 10.9 9 595.0 79.20-82.80 37.75-37.85
bolting service Direct Tension Indicators
DTIs for Metric British Standard Structural Bolts BS7644 Supplied in Plain, Coated (specify) and available in Weathering Steel
Size Grade Bumps Minimum Compression Load (kN) Outside Diameter (mm) Inside Diameter (mm)
M12 8.8 4 49.4 26.40-27.60 12.55-12.65
M16 8.8 4 92.1 35.20-36.80 16.75-16.85
M20 8.8 5 144.0 40.80-41.30 21.00-21.10
M22 8.8 5 177.0 47.11-47.62 23.29-23.39
M24 8.8 6 207.0 50.30-50.80 25.15-25.25
M27 8.8 6 234.0 56.60-57.15 28.30-28.40
M30 8.8 7 286.0 57.00-63.00 31.45-31.55
M36 8.8 8 418.0 79.20-82.80 37.75-37.85
M16 10.9 4 103.9 35.20-36.80 16.75-16.85
M20 10.9 6 161.8 40.80-41.30 21.00-21.10
M22 10.9 6 200.2 47.11-47.62 23.29-23.39
M24 10.9 7 233.4 50.30-50.80 25.15-25.25
M27 10.9 7 303.0 56.60-57.15 28.30-28.40
M30 10.9 8 370.0 57.00-63.00 31.45-31.55
M33 10.9 8 459.0 75.70-76.20 34.50-34.60
bolting service Direct Tension Indicators
DTIs for Metric EU Structural Bolts EN 14399-9 Supplied in Plain, Coated (specify)
Size Grade Bumps Minimum Compression Load (kN) Outside Diameter (mm) Inside Diameter (mm)
M12 H8 4 47.0 26.40-27.60 12.55-12.65
M16 H8 4 88.0 35.20-36.80 16.75-16.85
M20 H8 5 137.0 40.80-41.30 21.00-21.10
M22 H8 5 170.0 47.11-47.62 23.29-23.39
M24 H8 6 198.0 50.30-50.80 25.15-25.25
M27 H8 6 257.0 56.60-57.15 28.30-28.40
M30 H8 7 314.0 57.00-63.00 31.45-31.55
M36 H8 8 458.0 79.20-82.80 37.75-37.85
M12 H10 4 59.0 24.40-27.60 12.55-12.65
M16 H10 4 110.0 35.20-36.80 16.75-16.85
M20 H10 6 172.0 40.80-41.30 21.00-21.10
M22 H10 6 212.0 47.11-47.62 23.29-23.39
M24 H10 7 247.0 50.30-50.80 25.15-25.25
M27 H10 7 321.0 56.60-57.15 28.30-28.40
M30 H10 8 393.0 57.00-63.00 31.45-31.55
M36 H10 9 572.0 79.20-82.80 37.75-37.85
bolting service Direct Tension Indicators
DTIs for Metric DIN Structural Bolts DIN 6914 10.9 Supplied in Plain, Coated (specify)
Size Grade Bumps Minimum Compression Load (kN) Outside Diameter (mm) Inside Diameter (mm)
M12 10.9 4 60.0 26.40-27.60 12.55-12.65
M16 10.9 4 110.0 35.20-36.80 16.75-16.85
M20 10.9 6 175.0 44.00-46.00 20.95-21.05
M22 10.9 6 210.0 48.40-50.60 23.05-23.15
M24 10.9 7 240.0 52.80-55.20 25.15-25.25
M27 10.9 7 320.0 59.40-62.10 28.30-28.40
M30 10.9 8 390.0 66.00-69.00 31.45-31.55
M33 10.9 8 459.0 75.70-76.20 34.50-34.60
M36 10.9 9 560.0 79.20-82.80 37.75-37.85
bolting service Direct Tension Indicators
DTIs for Inch Cap Screws and Bolts ASTM F2437 Supplied in Plain, Coated (specify)
Size Grade Bumps Minimum Compression Load (KIPS) Outside Diameter (In) Inside Diameter (In)
1/4 GRADE 5 3 2.2 0.505-0.525 .0254-0.258
5/16 GRADE 5 3 3.5 0.650-0.670 0.317-0.321
3/8 GRADE 5 4 5.3 0.780-0.800 0.379-0.383
7/16 GRADE 5 4 7.2 0.898-0.918 0.443-0.448
1/2 GRADE 5 4 9.7 0.950-0.970 0.508-0.512
9/16 GRADE 5 5 12.3 1.052-1.072 0.573-0.577
5/8 GRADE 5 5 15.5 1.204-1.224 0.635-0.639
3/4 GRADE 5 6 22.6 1.474-1.494 0.760-0.764
7/8 GRADE 5 6 30.8 1.630-1.650 0.885-0.889
1 GRADE 5 7 40.2 1.846-1.866 1.010-1.014
1 1/8 GRADE 5 7 45.1 2.063-2.083 1.135-1.139
1 1/4 GRADE 5 8 56.5 2.305-2.325 1.260-1.264
1 3/8 GRADE 5 8 69.3 2.565-2.585 1.388-1.392
1 1/2 GRADE 5 8 83.3 2.798-2.818 1.525-1.529
1 3/4 GRADE 5 9 121.8 3.265-3.285 1.767-1.772
1 7/8 GRADE 5 9 154.5 3.500-3.520 1.892-1.897
2 GRADE 5 9 160.0 3.735-3.755 2.030-2.040
2 1/4 GRADE 5 10 208.4 4.205-4.225 2.275-2.280
2 1/2 GRADE 5 10 256.5 4.675-4.695 2.525-2.530
1/4 GRADE 8 3 3.1 0.505-0.525 .0254-0.258
5/16 GRADE 8 3 4.9 0.650-0.670 0.317-0.321
3/8 GRADE 8 4 7.5 0.780-0.800 0.379-0.383
7/16 GRADE 8 4 10.1 0.898-0.918 0.443-0.448
1/2 GRADE 8 4 13.7 0.950-0.970 0.508-0.512
9/16 GRADE 8 5 17.4 1.052-1.072 0.573-0.577
5/8 GRADE 8 5 21.8 1.204-1.224 0.635-0.639
3/4 GRADE 8 6 31.9 1.474-1.494 0.760-0.764
7/8 GRADE 8 6 43.5 1.630-1.650 0.885-0.889
1 GRADE 8 7 56.7 1.846-1.866 1.010-1.014
1 1/8 GRADE 8 8 73.1 2.063-2.083 1.135-1.139
1 1/4 GRADE 8 9 91.7 2.305-2.325 1.260-1.264
1 3/8 GRADE 8 10 112.4 2.565-2.585 1.388-1.392
1 1/2 GRADE 8 11 135.1 2.798-2.818 1.525-1.529
1 3/4 GRADE 8 13 177.8 3.265-3.285 1.767-1.772
1 7/8 GRADE 8 13 206.0 3.500-3.520 1.892-1.897
2 GRADE 8 14 236.8 3.735-3.755 2.030-2.040
2 1/4 GRADE 8 15 277.9 4.205-4.225 2.275-2.280
2 1/2 GRADE 8 18 379.6 4.675-4.695 2.525-2.530
bolting service Direct Tension Indicators
DTIs for Metric Cap Screws and Bolts Supplied in Plain, Coated (specify)
Size Grade Bumps Minimum Compression Load (kN) Outside Diameter (mm) Inside Diameter (mm)
M16 Class 8.8 5 78.0 30.66-31.16 16.25-16.35
M20 Class 8.8 6 121.5 37.59-38.09 20.25-20.35
M22 Class 8.8 6 150.0 42.65-43.15 22.25-22.35
M24 Class 8.8 7 174.8 44.47-44.97 24.35-24.45
M27 Class 8.8 7 227.3 52.40-52.90 28.82-28.93
M30 Class 8.8 8 277.5 56.02-56.52 30.35-30.45
M36 Class 8.8 8 404.3 66.46-66.96 36.25-36.35
M8 Class 10.9 3 25.8 18.50-19.00 8.29-8.39
M10 Class 10.9 4 40.9 21.63-22.13 10.29-10.39
M12 Class 10.9 4 59.4 24.13-24.63 12.29-12.39
M14 Class 10.9 5 81.0 27.15-27.65 14.29-14.39
M16 Class 10.9 5 111.0 30.66-31.16 16.29-16.39
M20 Class 10.9 6 172.5 37.59-38.09 20.29-20.39
M22 Class 10.9 6 213.8 42.65-43.15 22.29-22.39
M24 Class 10.9 7 249.0 44.47-44.97 24.39-24.49
M27 Class 10.9 7 323.3 52.40-52.90 28.82-28.93
M30 Class 10.9 8 395.3 56.02-56.52 30.39-30.49
M36 Class 10.9 8 572.3 66.46-66.96 36.39-36.39
bolting service Direct Tension Indicators
DTIs for Inch Studs and Anchor Bolts ASTM F2437 Supplied in Plain, Coated (specify)
Size Grade Bumps Minimum Compression Load (KIPS) Outside Diameter (In) Inside Diameter (In)
1/2 55 3 4.4 1.020-1.040 0.515-0.520
9/16 55 3 5.7 1.130-1.150 0.564-0.569
5/8 55 3 7.0 1.240-1.260 0.640-0.645
3/4 55 4 10.5 1.450-1.470 0.765-0.770
7/8 55 4 14.5 1.670-1.690 0.890-0.895
1 55 4 19.0 1.890-1.910 1.020-1.025
1 1/8 55 5 23.9 2.100-2.120 1.150-1.155
1 1/4 55 5 30.4 2.320-2.340 1.275-1.280
1 3/8 55 5 38.5 2.540-2.560 1.400-1.405
1 1/2 55 6 44.0 2.750-2.770 1.525-1.530
1 5/8 55 6 55.8 2.970-2.990 1.650-1.655
1 3/4 55 6 59.5 3.190-3.210 1.775-1.780
1 7/8 55 7 75.5 3.400-3.420 1.900-1.905
2 55 8 102.0 3.620-3.640 2.030-2.040
2 1/4 55 9 113.0 4.050-4.070 2.275-2.280
2 1/2 55 9 125.4 4.480-4.500 2.525-2.530
1/2 105 4 8.5 1.020-1.040 0.515-0.520
9/16 105 4 10.9 1.130-1.150 0.564-0.569
5/8 105 4 13.5 1.240-1.260 0.640-0.645
3/4 105 5 20.0 1.450-1.470 0.765-0.770
7/8 105 5 27.6 1.670-1.690 0.890-0.895
1 105 6 36.2 1.890-1.910 1.020-1.025
1 1/8 105 6 47.3 2.100-2.120 1.150-1.155
1 1/4 105 7 59.8 2.320-2.340 1.275-1.280
1 3/8 105 8 73.8 2.540-2.560 1.400-1.405
1 1/2 105 9 89.3 2.750-2.770 1.525-1.530
1 5/8 105 10 106.2 2.970-2.990 1.650-1.655
1 3/4 105 11 124.6 3.190-3.210 1.775-1.780
1 7/8 105 12 144.5 3.400-3.420 1.900-1.905
2 105 13 165.8 3.620-3.640 2.030-2.040
2 1/4 105 13 212.9 4.050-4.070 2.275-2.280
2 1/2 105 14 240.5 4.480-4.500 2.525-2.530
* Now available in our NEW Offset Extrusion design for enhanced performance with the new expanded AISC bolt hole standards.
bolting service Direct Tension Indicators


Certifications of TurnaSure Bolting Services

Bolting services DTI

Laboratory Testing Inc (LTI) in Hatfield, PA

TurnaSure’s DTIs are generally independently tested at an independent laboratory, namely Laboratory Testing Inc (LTI) at Hatfield, PA. LTI is accredited under NIST accreditation programs to test Direct Tension Indicators. The standard deviation on a typical 29 piece sample is close to plus or minus 1% of the mean.

Typical Test Certificate

Example of a DTI Test Certificate

Click to enlarge
bolting service Direct Tension Indicators

Find out how TurnaSure DTIs and our bolting technology can bring structural stability and savings to your next project. Contact our experts online or by calling 1-800-525-7193.
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