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  4. ASTM F3111 Specification

ASTM F3111 Structural Bolting Specification

Heavy Hex Structural Bolt/Nut/Washer Assemblies, Alloy Steel, Heat Treated, 200 ksi Minimum Tensile Strength

ASTM F3111 Chemical Requirements

Element C Mn P S Si Cr Mo V
Bolts Heat Analysis, % min 0.38 0.4 . . . . . . . . . 1.2 0.6 0.3
max 0.42 0.6 0.01 0.01 0.1 1.4 0.8 0.4
Product Analysis, % min 0.36 0.37 . . . . . . . . . 1.15 0.57 0.27
max 0.44 0.63 0.015 0.015 0.12 1.45 0.83 0.43
Nuts Heat Analysis, % min 0.3 0.6 . . . . . . 0.15 . . . . . . . . .
max 0.48 0.9 0.05 0.05 0.35 . . . . . . . . .
Product Analysis, % min 0.28 0.57 . . . . . . 0.13 . . . . . . . . .
max 0.5 0.93 0.055 0.055 0.37 . . . . . . . . .
Washers Heat Analysis, % min 0.42 0.6 . . . . . . 0.15 . . . . . . . . .
max 0.48 0.9 0.03 0.03 0.35 . . . . . . . . .
Product Analysis, % min 0.4 0.57 . . . . . . 0.13 . . . . . . . . .
max 0.5 0.93 0.035 0.035 0.37 . . . . . . . . .

ASTM F3111 Mechanical Requirements

ASTM F3111 Hardness Requirements for Bolts

Bolt Size, in. Bolt Length, in. Rockwell C
Min Max
1 to 1 1/4 , incl all 38 45

ASTM F3111 Tensile Requirements for Full Size Bolts

Grade Bolt Size, Threads per in. Stress Area,A,B in.2 Tensile Load,C lbf Proof Load, lbf Alternative Proof Load, lbf
Min Max Length Measurement Method Yield Strength Method
ASTM F3111 Grade 1 1 in. - 8 0.615 123 100 132 300 98 500 119 100
1 1/8 in. - 7 0.776 155 200 166 800 124 200 139 700
1 1/4 in. - 7 0.983 196 700 211 400 157 400 177 000
ASTM F3111 Grade 2 1 in. - 8 0.640 128 000 137 700 102 400 115 200
1 1/8 in. - 7 0.808 161 600 173 600 129 300 145 400
1 1/4 in. - 7 1.019 203 800 219 100 163 000 183 400
  • (A) The stress area for Grade 1 is calculated as: 
  • As = 0.7854[0.5 (d3 max + d2 max)]2
  • (B) The stress area for Grade 2 is calculated in accordance with Annex A1.
  • (C) Loads tabulated are based on the following:
Bolt Size, in. Column 3 Column 4 Column 5 Column 6
1 to 1 1/4 200 000 psi 215 000 psi 160 000 psi 180 000 psi

ASTM F3111 Tensile Strength Requirements for Specimens Machined from Bolts

Nominal Bolt Diameter, in. Tensile Strength, ksi Yield Strength (0.2 % offset), min, ksi Elongation in 2 in. or 50 mm, min, % Reduction of Area, min, %
min max
1 to 1 1/4 , incl 200 215 180 14 40

ASTM F3111 Hardness Requirements for Nuts

Bolt Size, in. Surface Hardness, Rockwell C
Min Max
1 to 1 1/4 , incl 30 40

ASTM F3111 Proof Load Requirements for Nuts

Grade Nominal Size, Threads per inch Stress Area, As,A,B in.2 Proof Load Stress, ksi Nut Proof Load,C lbf
ASTM F3111 Grade 1 1 in. - 8 0.615 200 123 100
1 1/8 in. - 7 0.776 200 155 200
1 1/4 in. - 7 0.983 200 196 700
ASTM F3111 Grade 2 1 in. - 8 0.640 200 128 000
1 1/8 in. - 7 0.808 200 161 600
1 1/4 in. - 7 1.019 200 203 800
  • (A) The stress area for Grade 1 is calculated as:
  • As = 0.7854[0.5 (d3 max + d2 max)]2
  • (B) The stress area for Grade 2 is calculated in accordance with Annex A1.
  • (C) To determine nut proof load in pounds, multiply the appropriate nut proof load stress by the tensile stress area of the thread.

ASTM F3111 Core Hardness Requirements for Washers

Rockwell C
Min 40 Max 45

ASTM F3111 Assembly Lot Tension Test Requirements

Grade Bolt Size, in. Initial Torque (ft-lbs) Initital Tension lbs, minA Initial Tension lbs, maxB Final Rotation (degrees)C Final Tension lbs, minD Tension lbs, min (for information only)E
ASTM F3111 Grade 1 1 400 30 000 86 000 180 90 000 86 000
1 1/8 600 38 000 109 000 180 114 000 109 000
1 1/4 900 48 300 138 000 180 145 000 138 000
ASTM F3111 Grade 2 1 400 31 000 90 000 180 94 000 90 000
1 1/8 600 40 000 113 000 180 119 000 113 000
1 1/4 900 50 000 143 000 180 150 000 143 000
  • (A) The values in Column 2 are based upon 35% of the values in Column 6, rounded to the nearest 1000 lbs (kip).
  • (B) The values in Column 3 are equal to the values in Column 6.
  • (C) Tolerance for Final Rotation in Column 4 as applied for this test is ± 15 degrees.
  • (D) The values in Column 5 are based upon 105% of the values in Column 6, rounded to the nearest 1000 lbs (kip).
  • (E) The values in Column 6 are equal to 70% of the specified minimum tensile strength for tests of full size F3111 bolts tested in axial tension and are rounded to the nearest 1000 lbs (kip).

ASTM F3111 Heavy Hex Bolts

ASTM F3111 Heavy Hex Bolts

Parameters Range Size
Nominal Size  ... 1 1 1/8 1 1/4
Basic Diameter, E, in.  ... 1.000 1.125 1.250
Full-Size Body Diameter E, in. max 1.022 1.149 1.277
min 0.976 1.098 1.223
Width Across Flats, F, in.A nom 1 5/8 1 13/16 2
max 1.625 1.812 2.000
min 1.575 1.756 1.938
Width Across Corners, G, in. max 1.876 2.093 2.309
min 1.796 2.002 2.209
Head Height, H, in.B nom 39/64 11/16 25/32
max 0.627 0.718 0.813
min 0.591 0.658 0.749
Radius of Fillet, R, in. nom 3/32 3/32 7/64
max 0.110 0.110 0.138
min 0.087 0.087 0.098
Transition Body Diameter, ER, in. nom 59/64 1 1/32 1 5/32
max 0.933 1.046 1.171
min 0.917 1.030 1.155
Body Transition Length, Y2, in. nom 0.305 0.354 0.354
max 0.394 0.450 0.450
min 0.207 0.244 0.244
Reduced Body Length, LR, in. nom 1/2 9/16 9/16
max 0.625 0.715 0.715
min 0.375 0.429 0.429
Transition Thread Length Y1, in.C Ref 0.31 0.34 0.34
Thread Length, LT, in.D Ref 2.049 2.322 2.322
Maximum Total Runout of Bearing Surface FIM, in.E . . . 0.028 0.032 0.035
  • (A) See ASME B18.2.6, sections 2.1.2 and 2.1.3.
  • (B) See ASME B18.2.6, section 2.1.4.
  • (C) Transition thread length, Y1, is a reference dimension, intended for calculation purposes only, that represents the length of incomplete threads and tolerance on grip gaging length.
  • (D) See ASME B18.2.6, section 2.1.10.2.
  • (E) See ASME B18.2.6, section 2.1.6.

ASTM F3111 Heavy Hex Nut Dimensions

ASTM F3111 Heavy Hex Nut Dimensions

Parameters Range Size
Nominal Size  . . . 1 1 1/8 1 1/4
. . .   1.000 1.125 1.250
Width Across Flats, F, in.A nom 1 5/8 1 13/16 2
max 1.625 1.812 2.000
min 1.575 1.756 1.938
Width Across Corners, G, in.B max 1.876 2.093 2.309
min 1.796 2.002 2.209
Thickness, H, in.C nom 1 3/16 1 11/32 1 15/32
max 1.214 1.367 1.501
min 1.147 1.295 1.424
Washer Face Height, in. nom 1/64 1/64 1/64
Total Runout of Bearing Face FIM, in.D . . . 0.024 0.027 0.030
  • (A) The width across flats of heavy hex nuts shall be the overall distance measured, perpendicular to the axis of the nut, between two opposite sides of the nut. No transverse section through the nut between 25% and 75% of the actual nut thickness, as measured from the bearing surface, shall be less than the minimum width across flats.
  • (B) A rounding or lack of fill at junction of hex comers with chamfer shall be permissible, provided the width across comers is within specified limits at and beyond a distance equal to 17.5% of the basic thread diameter from the chamfered faces.
  • (C) The nut thickness shall be the overall distance measured parallel to the axis of the nut, from the top of the nut to the bearing surface, and shall include the thickness of the washer face where provided.
  • (D) Nuts shall have a washer faced bearing surface and chamfered top. The diameter of washer face shall be within the limits of the maximum width across flats and 95% of the minimum width across flats.

ASTM F3111 Hardened Circular Washers Dimensions

ASTM F3111 Hardened Circular Washers Dimensions

Paarameters Range Size
Nominal Size . . . 1 1 1/8 1 1/4
Inside Diameter (ID), in. nom 1 1/16 1 3/16 1 3/8
max 1.085 1.251 1.438
min 1.063 1.188 1.375
Outside Diameter (OD), in. nom 2 2 1/4 2 1/2
max 2.063 2.313 2.563
min 1.937 2.187 2.437
Thickness (T), in. nom 1/4 1/4 5/16
max 0.264 0.264 0.343
min 0.209 0.209 0.287

ASTM F3111 Basic Thread Dimensions, Grade 2 Assemblies

ASTM F3111 Basic Thread Dimensions, Grade 2 Assemblies

Paarameters Size
Nominal Size, in. 1 1 1/8 1 1/4
Major Diameter, in. 0.9980 1.1228 1.2478
Threads per inch 8 7 7
Pitch, in. 0.1250 0.1429 0.1429
A, in. 0.0135 0.0155 0.0155
B, in. 0.0460 0.0526 0.0526
C, in. 0.0106 0.0121 0.0121
D, in. 0.0381 0.0435 0.0435
E, in. 0.0167 0.0190 0.0190
F, in. 0.0281 0.0321 0.0321
G, in. 0.0180 0.0206 0.0206
H, in. 0.1083 0.1237 0.1237
J, in. 0.0722 0.0825 0.0825
M, in. 0.0054 0.0062 0.0062
Q, in. 0.1104 0.1261 0.1261
  • As = (π /4)[(d2 + d3)/2]2
  • where:
    • As = Tensile stress area, in.2
    • dbsc = basic major diameter, in.
    • n = threads per in.
    • H = (√3 /2) * dbsc / n
    • d2 = dbsc - (3/4 H)
    • d1 = d2 - 2 (H / 20)
    • Ɵ = sin-1 (2 √3 / 15)
    • z = (H / 6) (cos Ɵ)
    • x′ = (H / 6) (sin 30º)
    • y = (H / 2) (cos Ɵ)
    • z′ = (2H / 3) - y - z
    • d3 = d1 - 2 (z - x′ + z′)

ASTM F3111 Bolting Surface Treatment Specifications

ASTM F3111 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

B18.2.6 - Heavy Hex Structural Bolts ( Inch Series)
B18.2.2 - Heavy Hex Nuts Washer faced ( Inch Series)

ASTM F3111 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 F3111 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)