ASTM F3125/F3125M Structural Bolts Specification

High Strength Structural Bolts, Steel and Alloy Steel, Heat Treated, 120 ksi (830 MPa) and 150 ksi (1040 MPa) Minimum Tensile Strength, Inch and Metric Dimensions

Related Specifications of ASTM F3125/F3125M Bolting

A194 A354 A449 A563 F436 F959 F2482

ASTM F3125/F3125M Classification

Grade Min. Strength TypeA Style
ASTM F3125/F3125M Grade A325 120 ksi 1 or 3 Heavy Hex Head
ASTM F3125/F3125M Grade A490 150 ksi 1 or 3 Heavy Hex Head
ASTM F3125/F3125M Grade F1852 120 ksi 1 or 3 Twist-Off
ASTM F3125/F3125M Grade F2280 150 ksi 1 or 3 Twist-Off
ASTM F3125/F3125M Grade A325M 830 MPa 1 or 3 Heavy Hex Head
ASTM F3125/F3125M Grade A490M 1040 MPa 1 or 3 Heavy Hex Head
  • (A) Type 1 - 120 ksi (830 MPa) - carbon steel, carbon boron steel, alloy steel or alloy steel with boron addition 
  • Type 3 - 120 ksi (830 MPa) or 150 ksi (1040 MPa) - weathering steel 
  • Type 1 - 150 ksi (1040 MPa) - alloy steel or alloy steel with boron addition

ASTM F3125/F3125M Dimensions, Threads, Marking, Matching Components

Type Parameter Inch Metric
120 ksi Min Tensile 150 ksi Min Tensile 830 MPa Min Tensile 1040 MPa Min Tensile
Type 1 Type 3 Type 1 Type 3 Type 1 Type 3 Type 1 Type 3
Style - Heavy Hex Bolts Dimensions, ASMEB B18.2.6 B18.2.6 B18.2.6 B18.2.6 B18.2.6M B18.2.6M B18.2.6M B18.2.6M
Thread Fit, ASMEB B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.13M MC 6g B1.13M MC 6g B1.13M MC 6g B1.13M MC 6g
Grade MarkingA,D A325 A325 A490 A490 A325M A325M A490M A490M
Style - Twist-Off Bolts Dimensions, ASMEB B18.2.6 B18.2.6 B18.2.6 B18.2.6 F F F F
Thread Fit, ASMEB B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A F F F F
Grade MarkingA,D A325TC A325TC A490TC A490TC F F F F
Alt. MarkingA,C A325 A325 A490 A490 F F F F
Recommended Nut and Washer Plain Nut A563 DH A563 Dh3 A563 DH A563 Dh3 A563M 10S A563M 10S3 A563M 10S A563M 10S3
Suitable AlternativeE Dh3, D, C, C3 C3 ... ... 8S, 8S3, 10S3 8S3 10S3 ...
Coated Nut A563 DH A563 Dh3 A563 DH A563 Dh3 A563M 10S A563M 10S3 A563M 10S A563M 10S3
Flat, Bevel or Thick Washer if used F436/F436M- 1 F436/F436M- 3 F436/F436M- 1 F436/F436M- 3 F436/F436M- 1 F436/F436M- 3 F436/F436M- 1 F436/F436M- 3
  • (A) A325 and A325M bolts lengths up to 4D which are fully threaded but which are not required to be fully threaded by the relevant ASME standard shall be marked with a "T", see Supplementary Requirement S1. Bolts with any other non-standard dimensions, including non-standard thread length (except for bolts up to 4D threaded fully and marked with "T" per S1 requirement), shall be marked with an "S", see Supplementary Requirement S2.
  • (B) Manufactured to the latest revision at the time of manufacture, UNC for inch series and Metric Coarse (MC) for Metric Series.
  • (C) Previously used markings may be sold and used indefinitely, bolts must be manufactured to current marking requirements upon initial publication of this standard.
  • (D) Other distinguishing markings for type 3 are permitted at the manufacturers option.
  • (E) ASTM A194/A194M 2H Heavy Hex inch Nuts may be used in place of A563 DH nuts on type 1 A325, A490, F1852 and F2280 bolts. 2H Heavy Hex metric Nuts may be used in place of A563M 10S nuts on type 1 A325M and A490M bolts. When coated 2H nuts are used in place of DH or 10S nuts, the same requirements of A563, A563M, and this specification, including Annex A1, shall apply. These requirements include, but are not limited to, thread dimensions and overtapping allowances, coating grade, lubrication requirements, and proof load testing.
  • (F) Metric dimensions and requirements for this style have not been established.

ASTM F3125/F3125M Chemical RequirementsA

Heat Analysis 120 ksi/830 MPa Minimum 150 ksi/1040 MPa Minimum
Grade A325, A325M, F1852 Grade A490, A490M, F2280
Type 1 Type 3 Type 1 Type 3
C or Alloy Steel with or without Boron CompositionA CompositionB Based on Corrosion IndexB Alloy Steel with or without Boron Based on Corrosion IndexB
C 0.30 - 0.52 0.33 - 0.40 0.38 -0.48 0.30 - 0.52 max 0.30 - 0.48C 0.30 - 0.53
Mn 0.60 min 0.90 - 1.20 0.70 - 0.90 0.60 min 0.60 min 0.60 min
P, max 0.035 0.035 0.035 0.035 0.035 0.035
S, max 0.040 0.040 0.040 0.040 0.040 0.040
Si 0.15 - 0.30 0.15 - .30 0.30 - 0.50 D D D
B 0.003 max D D D 0.003 max D
Cu D 0.25 - 0.45 0.20 - 0.40 0.20 - 0.60 D 0.20 - 0.60
Ni D 0.25 - 0.45 0.50 - 0.80 0.20E min D 0.20E min
Cr D 0.45 - 0.65 0.50 - 0.75 0.45 min D 0.45 min
V D D D D D D
Mo D D 0.06 max 0.10Emin D 0.10E min
Ti D D D D D D
  • (A) Based on heat analysis.
  • (B) Carbon requirement is 0.35-0.53 for 1-1/2 in. and M36 diameter bolts.
  • (C) Not Specified.
  • (D) Material that satisfies the criteria for either Nickel or Molybdenum shall be considered as satisfying the requirements for both elements.

ASTM F3125/F3125M Mechanical Requirements

ASTM F3125/F3125M Mechanical Property Requirements for Bolts Tested Full Size (Inch)

Size 120 ksi - A325, F1852 150 ksi - A490, F2280
Stress AreaA Tensile min Proof Load Length Measurement min Alternative Proof Load Yield Strength Method min Tensile min Tensile max. Proof Load Length Measurement min Alternative Proof Load Yield Strength Method min
in2 lbf lbf lbf lbf lbf lbf lbf
1/2-13 UNC 0.142 17050 12050 13050 21300 24600 17050 18500
5/8-11 UNC 0.226 27100 19200 20800 33900 39100 27100 29400
3/4-10 UNC 0.334 40100 28400 30700 50100 57800 40100 43400
7/8-9 UNC 0.462 55450 39250 42500 69300 79950 55450 60100
1-8 UNC 0.606 72700 51500 55750 90900 104850 72700 78800
11/8-7 UNC 0.763 91600B 64900B 70250B 114450 132000 91550 99200
11/4-7 UNC 0.969 116300B 82400B 89200B 145350 167650 116300 126000
13/8-6 UNC 1.155 138600B 98200B 106300B 173250 199850 138600 150200
11/2-6 UNC 1.405 168600B 119500B 129300B 210750 243100 168600 182600
Above values based on   120 ksi 85 ksi 92 ksi 150 ksi 173 ksi 120 ksi 130 ksi

ASTM F3125/F3125M Mechanical Property Requirements for Bolts Tested Full Size (Metric)

Size 830 MPa - A325M 1040 MPa - A490M
Stress AreaA Tensile min. Proof Load Length Measurement min Alternative Proof Load Yield Strength Method min Tensile min. Tensile max. Proof Load Length Measurement min Alternative Proof Load Yield Strength Method min
mm2 kN kN kN kN kN kN kN
M12 x 1.75 MC 84.3 70 50.6 55.6 87.7 103 70 79.2
M16 x 2.0 MC 157 130 94.2 104 163 190 130 148
M20 x 2.5 MC 245 203 147 162 255 296 203 230
M22 x 2.5 MC 303 251 182 200 315 366 251 285
M24 x 3.0 MC 353 293 212 233 367 427 293 332
M27 x 3.0 MC 459 381 275 303 477 555 381 431
M30 x 3.5 MC 561 466 337 370 583 679 466 527
M36 x 4.0 MC 817 678 490 539 850 989 678 768
Above values based on   830 MPa 600 MPa 660 MPa 1040 MPa 1210 MPa 830 MPa 940 MPa
  • (A) The stress area is calculated as follows for inch: AS = 0.7854 [D - (0.9743/n)]2; for Metric: AS = 0.7854 (D - 0.9382P)2; where AS = Stress Area, D = Nominal Bolt Size, and P = thread pitch.
  • (B) Previous versions of ASTM A325 and F1852 required tensile testing based on 105 ksi min. tensile strength for larger diameters, and proof load testing of 74 ksi (length measurement method) and 81 ksi (yield strength method). This specification was changed to align with AISC/RCSC design and installation values and metric equivalent strength levels.

ASTM F3125/F3125M Mechanical Property Requirements for Specimens Machined from Bolts

Mechanical Property Tensile min. Tensile max. Yield min. Elongation in 4D, min. % Reduction of Area, min. %
Inch 120 ksi, Grade A325, F1852 120 ksi 92 ksi 14 35
Inch 150 ksi, Grade A490, F2280 150 ksi 173 ksi 130 ksi 14 40
Metric 830 MPa, Grade A325M 830 MPa 660 MPa 14 35
Metric 1040 MPa, Grade A490M 1040 MPa 1210 MPa 940 MPa 14 40

ASTM F3125/F3125M Hardness Requirements for Bolts

1a20 ksi/830 MPa Tensile, Grade A325, A325M, F1852 150 ksi/1040 MPa Tensile, Grade A490, A490M, F2280
Brinell HB Rockwell HRC Brinell HB Rockwell HRC
Min Max Min Max Min Max Min Max
253 319 25 34 311 352 33 38

ASTM F3125/F3125M Twist-Off Style Assembly Installation Tension Test (Minimum Tension, lbf)

Bolt Diameter, in. F1852 F2280
1/2-13 UNC 12550 15650
5/8-11 UNC 19900 24900
3/4-10 UNC 29450 36800
7/8-9 UNC 40750 50950
1-8 UNC 53450 66800
11/8-7 UNC 67350 84100
11/4-7 UNC 85500 106850

ASTM F3125/F3125M Permitted Coatings

120 ksi & 830 MPa Bolt AssembliesA 150 ksi & 1040 MPa Bolt AssembliesA
Commonly Applied Coatings Grade or Class Qualified Coatings Grade or Class
F2329 Hot Dip Galvanized / 50 µm F1136/F1136M Bolt & Washer Grade 3, Nut Grade 5
B695 Class 55 F2833 Grade 1
Other Coatings Grade or Class F3019/F3019M Grade 4
F1136/F1136M Bolt & Washer Grade 3, Nut Grade 5 ... ...
F2833 Grade 1 ... ...
F3019/F3019M Grade 4 ... ...
  • (A) Coatings for Twist-off style bolt assemblies shall be agreed upon between the producer, supplier and user, and are not permitted except when applied under the direction of the manufacturer.

ASTM F3125/F3125M Nut Overlap Allowances UNC Thread

Dimensional Limits Galvanized B695/F2329A Zn/Al Coatings F1136/F1136M/F2833/F3019/F3019MB,C,D
Nut Pitch Dia. OvertapE,F Bolt Pitch Dia. OS After B695 CoatingG Bolt Pitch Dia. OS After F2329CoatingG Nut Pitch Dia. OverlapE Bolt Pitch Dia. OS after CoatingF
1/2-13 0.018 0.012 0.018 0.009 0.006
5/8-11 0.020 0.013 0.020 0.010 0.007
3/4-10 0.020 0.013 0.020 0.010 0.007
7/8-9 0.022 0.015 0.022 0.011 0.008
1-8 0.024 0.016 0.024 0.012 0.008
11/8-7 0.024 0.016 0.024 0.012 0.008
11/4-7 0.024 0.016 0.024 0.012 0.008
13/8-6 0.027 0.018 0.027 0.014 0.010
11/2-6 0.027 0.018 0.027 0.014 0.010

ASTM F3125/F3125M Nut Overlap Allowances MC Thread

Dimensional Limits Galvanized B695/F2329A Zn/Al Coatings F1136/F1136M/F2833/F3019/F3019MB,C,D
Nut Pitch Dia. OvertapE,F Bolt Pitch Dia. OS After B695 CoatingG Bolt Pitch Dia. OS After F2329CoatingG Nut Pitch Dia. OverlapE Bolt Pitch Dia. OS after CoatingF
M12 × 1.75 MC 0.45 0.30 0.45 0.23 0.16
M16 × 2.0 MC 0.50 0.33 0.50 0.25 0.17
M20 × 2.5 MC 0.50 0.33 0.50 0.25 0.17
M22 × 2.5 MC 0.55 0.36 0.55 0.28 0.19
M24 × 3.0 MC 0.60 0.40 0.60 0.30 0.20
M27 × 3.0 MC 0.60 0.40 0.60 0.30 0.20
M30 × 3.4 MC 0.70 0.46 0.70 0.35 0.24
M36 × 4.0 MC 0.70 0.46 0.70 0.35 0.24
  • (A) Supplementary nut lubrication to A563 S1 is required for hot dip and mechanically deposited zinc coatings.
  • (B) Grade 5 of F1136/F1136M coating meets the supplementary lubrication requirements of A563 S1.
  • (C) Grade 1 of F2833 coating meets the supplementary lubrication requirements of A563 S1.
  • (D) Nuts overtapped for coating for use with 150 ksi/1040 MPa minimum tensile strength fasteners shall be proof load tested to a minimum of 175,000 psi after overtapping.
  • (E) Nut overtap shall not exceed this amount unless agreed upon between the purchaser and user. If a larger overtap is used or required, coated bolts and overtapped and coated nuts shall pass the RC test requirements per Annex A2 as proof of assembly, ductility and thread strength.
  • (F) Bolt pitch oversize limit in case of dispute. Material within the plain gauge limits, which meets the coating thickness requirements and assembles freely need not be measured to this tolerance.
  • (G) Hot-Dip galvanized is typically tapped after coating. Others coatings are typically applied after nut tapping.

ASTM F3125/F3125M Pre-tension Requirements by Strength and Diameter

Strength Bolt Dia. (in.) 1/2  5/8  3/4  7/8  1 11/8  11/4  13/8  11/2 
120 ksi min. Initial Tension (kips) 1 2 3 4 5 6 8 10 12
150 ksi min. Initial Tension (kips) 1 2 4 5 6 8 10 12 15
Bolt Dia. (mm) 12 16 20 22 24 27 30  ... 36
830 MPa min. Initial Tension (kN) 4 9 13 18 22 27 31  ... 44
1040 MPa min. Initial Tension (kN) 9 13 18 22 27 36 40  ... 58

ASTM F3125/F3125M Maximum Permitted Torque at Minimum Design TensionA

Strength Bolt Dia. (in.) 1/2  5/8  3/4  7/8  1 11/8  11/4  13/8  11/2 
120 ksi min. Tension (kips)A 12 19 28 39 51 64 81 97 1/18
Maximum Torque (ft. lbs.) 125 247 437 710 1062 1502 2120 2779 3688
150 ksi min. Tension (kips)A 15 24 35 49 64 80 102 121 148
Maximum Torque (ft. lbs.) 156 312 546 893 1333 1875 2656 3466 4625
Bolt Dia. (mm) 12 16 20 22 24 27 30 ... 36
830 MPa min. Tension (kN)A 49 93 142 178 205 267 325 ... 476
Maximum Torque (Nm) 150 380 719 976 1234 1803 2440 ... 4284
1040 MPa min. Tension (kN)A 61 114 178 221 257 334 408 ... 595
Maximum Torque (Nm) 190 461 895 1220 1546 2251 3064 ... 5369
  • (A) Minimum design in the RCSC Specification for Structural Joints Using High-Strength Bolts. It represents 70% of minimum specified tensile strength.

ASTM F3125/F3125M Minimum Required Degrees of Rotation

Bolt Length 
Required Rotation
Up to 4D >4D to 8D >8D to 12D
120 ksi (830 MPa) min 240 360 420
150 ksi (1040 MPa) min 240 300 360

ASTM F3125/F3125M Minimum Tension at Full Rotation

Strength Bolt Dia. (in.) 1/2  5/8  3/4  7/8  1 11/8  11/4  13/8  11/2 
120 ksi min. Tension (kips) 14 22 32 45 59 74 94 112 136
150 ksi min. Tension (kips) 17 28 40 56 74 92 117 139 170
Bolt Dia. (mm) 12 16 20 22 24 27 30 ... 36
830 MPa min. Tension (kN) 57 108 164 205 235 307 373 ... 547
1040 MPa min. Tension (kN) 72 133 205 256 297 384 471 ... 685

ASTM F3125/F3125M Minimum Required Degrees of Rotation

Bolt Length Up to and including 4D Greater than 4D up to and including 8D
Required Rotation All Grades 120 180

ASTM F3125/F3125M Maximum Torque Values

Strength Bolt Dia. (in.) 1/2  5/8  3/4  7/8  1 11/8  11/4  13/8  11/2 
120 ksi min. Torque (ft. lbs.) 150 290 500 820 1230 1730 2450 3210 4250
150 ksi min. Torque (ft. lbs.) 180 370 630 1020 1540 2160 3050 3980 5310
Bolt Dia. (mm) 12 16 20 22 24 27 30 ... 36
830 MPa min. Torque (Nm) 176 427 827 1125 1416 2074 2807 ... 4922
1040 MPa min. Torque (Nm) 217 536 1024 1417 1790 2583 3539 ... 6162

ASTM F3125/F3125M Heat Treatment

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ASTM F3125/F3125M Bolting Surface Treatment Specifications

ASTM F3125/F3125M 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

B18.31.2 Imperial Continious Thread, Double End Reduced & Full Body Studs
B18.31.3 Threaded Rods (Inch Series)
B16.5 Imperial Full Thread Stud Bolts
B16.5 Metric Full Thread Stud Bolts
B18.2.1 Imperial Square and Hex Bolts and Screws
B18.3 Imperial Hexagon Socket and Spline Socket Screws

ASTM F3125/F3125M 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 F3125/F3125M Testing Standards

A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
E23 Test Methods for Notched Bar Impact Testing of Metallic Materials
E709 Guide for Magnetic Particle Testing
E1268 Practice for Assessing the Degree of Banding or Orientation of Microstructures
E1417/E1417M Practice for Liquid Penetrant Testing
E1444/E1444M Practice for Magnetic Particle Testing
E2884 Guide for Eddy Current Testing of Electrically Conducting Materials Using Conformable Sensor Arrays
F606/F606M Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
F788/F788M Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series
F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
F2328 Test Method for Determining Decarburization and Carburization in Hardened and Tempered, Threaded, Steel Bolts, Screws, Studs, and Nuts

ASME Threading Specifications

ASME B1.1 Unified Inch Screw Threads (UN and UNR Thread Form)
ASME B1.3 Screw Thread Gaging System for Dimensional Acceptability - Inch Screw Threads (IN, UNR, and UNJ)

ASTM F3125/F3125M Supplementary Requirements

S1 Bolts Threaded Full Length
S2 Alternate Dimensions
S3 Lubricant
S4 Rotational Capacity Testing for Plain and Other Coated Assemblies