Tension Control Bolts

Tension Control Bolts, TC Bolts or Twist Off Bolts Tension Control Bolts TC Bolt Twist off Bolt A325 A490 domestic are now the most popular choice in high-strength structural bolting and formally recognized by the AISC (American Institute of Steel Construction) and the RCSC (Research Council on Structural Connections) as an approved installation method. A Tension Control bolt consists of 1 bolt, 1 nut and 1 washer, pre-assembled and are shown this way on the certification paperwork as 1 lot number. Tension Control Bolt assemblies come with their own built in tension control device (spline) to ensure dependable and repeatable tension levels are achieved with each installation. They are installed with a specialized electric shear wrench that has an outer socket that turns the nut counterclockwise, while grabbing the spline with the inner socket turning it clockwise. When the proper tension level has been achieved the spline snaps off giving you a visual indication of proper installation. TC bolts use a proprietary lubrication on the nut, to control the clamping force of the bolt and ensure the appropriate tension level is achieved because of this it important that only the manufacture of a TC bolt.

Stock sizes listed below.

Specification: A325/F1852 & A490/F2280

Finish: Type-1, Type-3 & Mechanical Galvanized

Ordering Information
NOTE 2—Bolts are sometimes detailed with names such as A325 HS, A325 SC, A325 X or A490 N. These names relate to connection design and bolt installation, but do not change the manufacturing requirements and are preferably not shown on bolt orders.

Tension Control Bolt Advantages:

  1. Proper tension ensured
  2. Dependable & Repeatable results
  3. Can be used in shear or in tension
  4. One man installation on one side of the structure
  5. Light weight electric wrench can install multiple diameters
  6. Quick & easy installation, no match marking required
  7. Reduced job site noise

Table 4: Tensile Strength Requirements for Bolts Tested Full Size

  120 ksi - A325 (Hex) & F1852 (Twist-Off)150 ksi - A490 (Hex) & F2280 (Twist-Off)
DiameterStress Area in ²Tensile min lbfProof Load min lbfProof Load min lbfTensile min lbfTensile max lbfProof Load min lbfProof Load min
1/2"0.14217,05012,05013,05021,30024,60017,05018,500
5/8"0.22627,10019,20020,80033,90039,10027,10029,400
3/4"0.33440,10028,40030,70050,10057,80040,10043,400
7/8"0.46255,45039,25042,50069,30079,95055,45060,100
1"0.60672,70051,50055,70090,900104,85072,70078,800
1-1/8"0.76391,60064,90070,250114,450132,00091,60099,200
1-1/4"0.96911,630082,40089,200145,350167,650116,300126,000
1-3/8"1.15513,860098,200106,300173,250199,850138,600150,200
1-1/2"1.10516,860011,9500129,300210,750243,100168,600182,600
Above values based on 120,000psi85,000psi92,000psi150,000psi173,000psi120,000psi130,000psi
Source: ASTM F3125-15

F3125-15 Table 7 Twist-Off Style Assembly Installation Tension Test (Minimum Tension, lbf)

DiameterF1852F2280
1/2"12,55015,650
5/8"19,90024,900
3/4"29,45036,800
7/8"40,75050,950
1"53,45066,800
1-1/8"67,35084,100
1-1/4"85,500106,850
Source: ASTM F3125-15

5/8 (11) A325/F1852 - TC BOLTS IN STOCK

A325/F1852 Part #SIZELBS PER 100KEG QTYMin Tensile F1852/F2280
PTU0621505/8(11)X 1-1/2 40500120/150 ksi
PTU0621755/8(11)X 1-3/4 43470120/150 ksi
PTU0622005/8(11)X 2" 45450120/150 ksi
PTU0622255/8(11)X 2-1/4 47410120/150 ksi
PTU0622505/8(11)X 2-1/249380120/150 ksi
PTU0622755/8(11)X 2-3/4 51360120/150 ksi
PTU0623005/8(11)X 3" 54325120/150 ksi

3/4 (10) A325/F1852 & A490/F2280 - TC BOLTS IN STOCK

A325/F1852 Part #A490/F2280 Part #SIZELBS PER 100KEG QTYMin Tensile F1852/F2280
PTU075175PTF0751753/4(10)X 1-3/466300120/150 ksi
PTU075200PTF0752003/4(10)X 2" 70280120/150 ksi
PTU075225PTF0752253/4(10)X 2-1/4 73270120/150 ksi
PTU075250PTF0752503/4(10)X 2-1/2 76250120/150 ksi
PTU075275PTF0752753/4(10)X 2-3/4 79250120/150 ksi
PTU075300PTF0753003/4(10)X 3" 83240120/150 ksi
PTU075325PTF0753253/4(10)X 3-1/4 86230120/150 ksi
PTU075350PTF0753503/4(10)X 3-1/2 89220120/150 ksi
PTU075375PTF0753753/4(10)X 3-3/4 92200120/150 ksi
PTU075400PTF0754003/4(10)X 4" 95190120/150 ksi
PTU075425PTF0754253/4(10)X 4-1/4 98180120/150 ksi
PTU075450PTF0754503/4(10)X 4-1/2 102170120/150 ksi
PTU075475PTF0754753/4(10)X 4-3/4 105170120/150 ksi
PTU075500PTF0755003/4(10)X 5" 108150120/150 ksi
PTU075550PTF0755503/4(10)X 5-1/2114150120/150 ksi
PTU075600PTF0756003/4(10)X 6" 118130120/150 ksi

7/8 (9) A325/F1852 & A490/F2280 - TC BOLTS IN STOCK

A325 Part #A490 Part #SIZELBS PER 100KEG QTYMin Tensile F1852/F2280
PTU087200PTF0872007/8(9)X 2106200120/150 ksi
PTU087225PTF0872257/8(9)X 2-1/4 110190120/150 ksi
PTU087250PTF0872507/8(9)X 2-1/2 114180120/150 ksi
PTU087275PTF0872757/8(9)X 2-3/4 120180120/150 ksi
PTU087300PTF0873007/8(9)X 3124170120/150 ksi
PTU087325PTF0873257/8(9)X 3-1/4 128160120/150 ksi
PTU087350PTF0873507/8(9)X 3-1/2 129150120/150 ksi
PTU087375PTF0873757/8(9)X 3-3/4 131140120/150 ksi
PTU087400PTF0874007/8(9)X 4136140120/150 ksi
PTU087425PTF0874257/8(9)X 4-1/4140130120/150 ksi
PTU087450PTF0874507/8(9)X 4-1/2143130120/150 ksi
PTU087475PTF0874757/8(9)X 4-3/4 149120120/150 ksi
PTU087500PTF0875007/8(9)X 5153120120/150 ksi
PTU087550PTF0875507/8(9)X 5-1/2 162100120/150 ksi
PTU087600PTF0876007/8(9)X 6170100120/150 ksi

1 (8) A325/F1852 & A490/F2280 - TC BOLTS IN STOCK

A325/F1852 Part #A325/F2280 Part #SIZELBS PER 100KEG QTYMin Tensile F1852/F2280
PTU100200PTF1002001(8)X 2140150120/150 ksi
PTU100225PTF1002251(8)X 2-1/4143140120/150 ksi
PTU100250PTF1002501(8)X 2-1/2 149130120/150 ksi
PTU100275PTF1002751(8)X 2-3/4 154130120/150 ksi
PTU100300PTF1003001(8)X 3160120120/150 ksi
PTU100325PTF1003251(8)X 3-1/4 166120120/150 ksi
PTU100350PTF1003501(8)X 3-1/2171110120/150 ksi
PTU100375PTF1003751(8)X 3-3/4 177110120/150 ksi
PTU100400PTF1004001(8)X 4183100120/150 ksi
PTU100425PTF1004251(8)X 4-1/4 18890120/150 ksi
PTU100450PTF1004501(8)X 4-1/2 19490120/150 ksi
PTU100475PTF1004751(8)X 4-3/4 19990120/150 ksi
PTU100500PTF1005001(8)X 520590120/150 ksi
PTU100550PTF1005501(8)X 5-1/221780120/150 ksi
PTU100600PTF1006001(8)X 622880120/150 ksi
PTU100650PTF1006501(8)X 6-1/2 25165120/150 ksi
PTU100700PTF1007001(8)X 726260120/150 ksi
PTU100750PTF1007501(8)X 7-1/2 27355120/150 ksi
PTU100800PTF1008001(8)X 828855120/150 ksi
PTU100850PTF1008501(8)X 8-1/229950120/150 ksi

1-1/8 (7) F1852/A325 TC and F2280/A490 TC BOLTS IN STOCK

A325/F1852 Part #A490/F2280 Part #SIZELBS PER 100KEG QTYMin Tensile F1852/F2280
PTU113250PTF1132501-1/8(7)X 2-1/2 21880120/150 ksi
PTU113275PTF1132751-1/8(7)X 2-3/422580120/150 ksi
PTU113300PTF1133001-1/8(7)X 323280120/150 ksi
PTU113325PTF1133251-1/8(7)X 3-1/4 25070120/150 ksi
PTU113350PTF1133501-1/8(7)X 3-1/225270120/150 ksi
PTU113375PTF1133751-1/8(7)X 3-3/4 25470120/150 ksi
PTU113400PTF1134001-1/8(7)X 426070120/150 ksi
PTU113425PTF1134251-1/8(7)X 4-1/426760120/150 ksi
PTU113450PTF1134501-1/8(7)X 4-1/227360120/150 ksi
PTU113475PTF1134751-1/8(7)X 4-3/428050120/150 ksi
PTU113500PTF1135001-1/8(7)X 528850120/150 ksi
PTU113550PTF1135501-1/8(7)X 5-1/2 30250120/150 ksi
PTU113600PTF1136001-1/8(7)X 631650120/150 ksi
PTU113650PTF1136501-1/8(7)X 6-1/250120/150 ksi
PTU113700PTF1137001-1/8(7) X 732040120/150 ksi
PTU113750PTF1137501-1/8(7) X 7-1/234140120/150 ksi
PTU113800PTF1138001-1/8(7)X 840120/150 ksi

ASTM F1852 & F2280 Dimensions for TC Bolts

DiameterHeight (H)Bearing Surface Diameter (D)Length of Spline (LS)Width Across Flats (S)
MaxMinMinREFERENCE ONLYREFERENCE ONLY
5/80.4030.3781.102060.43
3/40.4830.4551.3380650.53
7/80.5630.5311.5350.720.16
10.6270.5911.7710.80.7
1-1/80.7180.6581.9910.90.8

To Determine Bolt Length Add to Grip

Bolt Dia0 Washers1 Washer2 Washers
1/2"11/16"55/64"1-3/64"
5/8"7/8"1-1/32"1-3/16"
3/4"1"1-5/32"1-5/16"
7/8"1-1/8"1-9/32"1-7/16"
1"1-1/4"1-13/32"1-9/16"
1-1/8"1-1/2"1-21/32"1-13/16"
1-1/4"1-5/8"1-25/32"1-15/16"
1-3/8"1-3/4"1-29/32"2-1/16"
1-1/2"1-7/8"2-1/32"2-3/16"

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