ASTM F3148 Structural Bolting Specification

High Strength Structural Bolt Assemblies, Steel and Alloy Steel, Heat Treated, 144 ksi Minimum Tensile Strength, Inch Dimensions

Related Specifications of ASTM F3148 Bolting

A563 F436

ASTM F3148 Scope

Type 1 144ksi - carbon steel, carbon boron steel, alloy steel or alloy steel with boron addition
Type 3 144ksi - weathering steel

ASTM F3148 Ordering Information

Coatings B695A,F F1136/F1136MD,F F2833E,F
Bolt Class 55 Grade 3 Grade 1
Nut Class 55 Grade 5 Grade 1
Washer Class 55 Grade 3 Grade 1
Size  Nut Pitch Dia.  Bolt Pitch Nut Pitch Dia.  Bolt Pitch Nut Pitch Dia.  Bolt Pitch
OS After OS After OS After
Overtap CoatingC OvertapB CoatingC OvertapB CoatingC
in. in. in. in. in. in.
1/2-13 UNC 0.018 0.012 0.009 0.006 0.009 0.006
5/8-11 UNC 0.020 0.013 0.010 0.007 0.010 0.007
3/4-10 UNC 0.020 0.013 0.010 0.007 0.010 0.007
7/8-9 UNC 0.022 0.015 0.011 0.008 0.011 0.008
1-8 UNC 0.024 0.016 0.012 0.008 0.012 0.008
1/8-7 UNC 0.024 0.016 0.012 0.008 0.012 0.008
1/4-7 UNC 0.024 0.016 0.012 0.008 0.012 0.008
  • (A) Supplementary nut lubrication to A563 S1, S2 or S3 is required for mechanically deposited zinc coatings.
  • (B) Nut overtap shall not exceed this amount unless agreed upon between the purchaser and user. If a larger overtap is used or required, coated structural bolt assembles shall pass the RC test requirements per F3148, Annex A1 as proof of assembly, ductility and thread strength.
  • (C) Bolt pitch oversize limit in case of dispute. Material within the plain gage limits which meets the coating thickness requirements and assembles freely need not be measured to this tolerance.
  • (D) Grade 5 of this coating meets the supplementary lubrication requirements of A563 S1.
  • (E) Grade 1 of this coating meets the supplementary lubrication requirements of A563 S1.
  • (F) Nuts overtapped for coating shall be proof load tested to a minimum of 175 000 psi.
  • (G) Other finishes - specify other protective finish, if required.
  • OS= Oversize

ASTM F3148 Dimensions

Round Head Dimensions, Type 1 Type 3
ASMEA B18.2.6 B18.2.6
Thread Fit, ASME B1.1 UNC 2A B1.1 UNC 2A
Grade Marking 144 144
Nut A563 DH A563 Dh4
Flat Washer F436/F436M - 1 F436/F436M - 3
  • (A) All dimensions except spline geometry

ASTM F3148 Chemical RequirementsA

Elements Type 1 Type 3
Heat Analysis C Steel with or without Alloy Steel with or without Composition Composition Based on Corrosion
B B A B IndexB
C 0.30 - 0.52 0.30 - 0.48 0.33 - 0.40 0.38 - 0.48 0.30 - 0.52
Mn 0.60 min 0.60 min 0.90 - 1.20 0.70 - 0.90 0.60 min
P, max 0.035 0.035 0.035 0.035 0.035
S, max 0.040 0.040 0.040 0.040 0.040
Si 0.15 - 0.30 0.15 - 0.30 0.30 - 0.50
B, max 0.003 0.003
Cu 0.25 - 0.45 0.20 - 0.40 0.20 - 0.60B
Ni 0.25 - 0.45 0.50 - 0.80 0.20B,Cmin
Cr 0.45 - 0.65 0.50 - 0.75 0.45 Bmin
Mo 0.06 max 0.15 B,Cmin
  • (A) Individual product analysis that is outside the specified range is permitted provided it is within 10% of the value required of the heat analysis.
  • (B) Type 3 bolts conforming to composition A or B, or type 3 bolts which have a copper minimum Heat Analysis of 0.20% and a Corrosion Index of 6 or higher as calculated from the Heat Analysis as described in Guide G101 Predictive method shall be accepted
  • (C) Either Nickel or Molybdenum must be present in the amount specified.

ASTM F3148 Mechanical Requirements

ASTM F3148 Tensile Strength Requirements for Bolts Tested Full Size

Nominal Size, Stress AreaA Tensile min Proof LoadB min Proof LoadC min
in. in.2 lbf lbf lbf
1/2-13 UNC 0.142 20450 15350 16350
5/8-11 UNC 0.226 32550 24400 26000
3/4-10 UNC 0.334 48100 36100 38400
7/8-9 UNC 0.462 66550 49900 53150
1-8 UNC 0.606 87250 65450 69700
11/8-7 UNC 0.763 109900 82400 87750
11/4-7 UNC 0.969 139550 104650 111450
Above values based on 144000psi 108000psi 115000psi
  • (A) The stress area is calculated as follows: 
  • AS = 0.7854 [D-(0.9743/P)]2 
  • Where AS = Stress Area, D = Nominal Bolt Size, and P = thread pitch
  • (B) Proof load length measurement
  • (C) Alternative Proof load Yield Strength Method

ASTM F3148 Tensile Strength Requirements for Specimens Machined from Bolts

Tensile min. Tensile max. Yield min. Elongation in 4D, min. % Reduction of Area, min. %
144000 psi 115000 psi 14 35

ASTM F3148 Hardness Requirements for Bolt

Brinell HB Rockwell HRC
Min Max Min Max
293 326 31 35

ASTM F3148 Tension Requirement by Diameter

Bolt Dia. (in.) 1/2 in. 5/8 in. 3/4 in. 7/8 in. 1 in. 11/8 in. 11/4 in.
Initial Tension (kips) 2 3 4 5 6 8 10

ASTM F3148 Maximum Permitted Torque at Minimum Design Tension

Bolt Dia. (in.) 1/2 in. 5/8 in. 3/4 in. 7/8 in. 1 in. 11/8 in. 11/4 in.
Tension (kips)A 15 24 35 49 64 80 102
Maximum Torque (ft. lbs.) 156 312 546 893 1333 1875 2656
  • (A) Minimum A490 design tension in the RCSC Specification for Structural Joints Using High-Strength Bolts. 75% of minimum specified tensile strength.

ASTM F3148 Required Rotation

Bolt Length Up to 4D > 4D to 8D > 8D to 12D
Required Rotation 240 360 420

ASTM F3148 Minimum Tension at Full Rotation

Bolt Dia. (in.) 1/2 in. 5/8 in. 3/4 in. 7/8 in. 1 in. 11/8 in. 11/4 in.
Tension (kips) 17 28 40 56 74 92 117

ASTM F3148 Maximum Torque Values

Bolt Dia. (in.) 1/2 in. 5/8 in. 3/4 in. 7/8 in. 1 in. 11/8 in. 11/4 in.
Torque (ft. lbs.) 180 370 630 1020 1540 2160 3050

ASTM F3148 Required Rotation

Bolt Length Up to 4D > 4D to 8D
Required Rotation 120 180

ASTM F3148 Required Rotation from Initial Tension

Bolt Length Up to 4D > 4D to 8D
Required Rotation 90 120

ASTM F3148 Assembly Tension Test Minimum Tension, lbf

Bolt Diameter (in.) 1/2 5/8 3/4 7/8 1 11/8 11/4
Initial Minimum 7000 11000 16000 22000 29000 36000 46000
Final Minimum 16000 25000 37000 51000 67000 84000 107000

ASTM F3148 Angle Tightening Rotation

Bolt Length Required RotationA Diameter in.
1/2 5/8 3/4 7/8 1 11/8 11/4
Up to 4D 90° Up to 2 Up to 21/2 Up to 3 Up to 31/2 Up to 4 Up to 41/2 Up to 5
>4D to 8D 120° 21/4 to 4 23/4 to 5 31/4 to 6 33/4 to 7 41/4 to 8 43/4 to 9 51/4 to 10

ASTM F3148 Heat Treatment

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ASTM F3148 Bolting Surface Treatment Specifications

ASTM F3148 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 F3148 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 F3148 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 F3148 Supplementary Requirements