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  4. ASTM A449 Specification

ASTM A449 Bolts Specification

Carbon Steel, Alloy Steel And Weatherng Steel Structural Bolts, Hex Cap Screws and Studs Heat Treated to 120/105/90 ksi Minimum Tensile Strength

Related Specifications of ASTM A449 Bolting

A563 F436 F2482 F3125 A325 A490 F2437 A242/A242M A588/A588M A606/A606M A709/A709M

ASTM A449 Scope

Type Description
Type I Plain carbon steel, carbon boron steel, alloy steel, or alloy boron steel
Type 2 Withdrawn 2003
Type 3 Weathering steel

ASTM A449 Ordering Information

Fastener Size and Surface Finish Nut Grade and StyleA
1/4 to 11/2 in., plain (or with a coating of insufficient  thickness to require over-tapped nuts) B, hex
Over 11/2 to 3 in., plain (or with a coating of insuffi-  cient thickness to require over-tapped nuts) A, heavy hex
1/4 to 3 in., zinc-coated (or with a coating thickness  requiring over-tapped nuts) DH, heavy hex
1/4 to 3 in., Type 3 C3, Dh4, heavy hex
  • (A) Nuts of other grades and styles having specified proof load stresses (Specification A563, Table 3) greater than the specified grade and style of nut are suitable.

ASTM A449 Chemical Composition

ASTM A449 Chemical Requirements for Type 1 Fasteners

 Types of Steel Elements Heat Analysis Product Analysis
Carbon Steel C 0.30-0.52 0.28-0.55
Mn, min 0.60 0.57
P, max 0.040 0.048
S, max 0.050 0.058
Si 0.15-0.30 0.13-0.32
 Boron Steel C 0.30-0.52 0.28-0.55
Mn, min 0.60 0.57
P, max 0.040 0.048
S, max 0.050 0.058
Si 0.10-0.30 0.08-0.32
B 0.0005-0.003 0.0005-0.003
 Alloy Steel
C 0.30-0.52 0.28-0.55
Mn, min 0.60 0.57
P, max 0.035 0.040
S, max 0.040 0.045
Si 0.15-0.35 0.13-0.37
Alloying Elements A A
Alloy Boron Steel
C 0.30-0.52 0.28-0.55
Mn, min 0.60 0.57
P, max 0.035 0.040
S, max 0.040 0.045
Si 0.15-0.35 0.13-0.37
B 0.0005-0.003 0.0005-0.003
Alloying Elements A A
  • (A) Steel, as defined by the American Iron and Steel Institute, shall be considered to be alloy when the maximum of the range given for the content of alloying elements exceeds one or more of the following limits: manganese, 1.65 %; silicon, 0.60 %; copper, 0.60 % or in which a definite range or a definite minimum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels: aluminum, chromium up to 3.99 %, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium, or any other alloying elements added to obtain a desired alloying effect.

ASTM A449 Chemical Requirements for Type 3 Fasteners A

Element Analysis Type 3 FastenersA
A B C D E F
C Heat analysis 0.33-0.40 0.38-0.48 0.15-0.25 0.15-0.25 0.20-0.25 0.20-0.25
Product analysis 0.31-0.42 0.36-0.50 0.14-0.25 0.14-0.25 0.18-0.27 0.19-0.25
Mn Heat analysis 0.90-1.20 0.70-0.90 0.80-1.35 0.40-1.20 0.60-1.00 0.90-1.20
Product analysis 0.86-1.24 0.67-0.93 0.76-1.39 0.36-1.24 0.56-1.04 0.86-1.24
P Heat analysis 0.035 max 0.06-0.12 0.035 max 0.035 max 0.035 max 0.035 max
Product analysis 0.040 max 0.06-0.125 0.040 max 0.040 max 0.040 max 0.040 max
S Heat analysis 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max 0.040 max
Product analysis 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max 0.045 max
Si Heat analysis 0.15-0.35 0.30-0.50 0.15-0.35 0.25-0.50 0.15-0.35 0.15-0.35
Product analysis 0.13-0.37 0.25-0.55 0.13-0.37 0.20-0.55 0.13-0.37 0.13-0.37
Cu Heat analysis 0.25-0.45 0.20-0.40 0.20-0.50 0.30-0.50 0.30-0.60 0.20-0.40
Product analysis 0.22-0.48 0.17-0.43 0.17-0.53 0.27-0.53 0.27-0.53 0.17-0.43
Ni Heat analysis 0.25-0.45 0.50-0.80 0.25-0.50 0.50-0.80 0.30-0.60 0.20-0.40
Product analysis 0.22-0.48 0.47-0.83 0.22-0.53 0.47-0.83 0.27-0.63 0.17-0.43
Cr Heat analysis 0.45-0.65 0.50-0.75 0.30-0.50 0.50-1.00 0.60-0.90 0.45-0.65
Product analysis 0.42-0.68 0.47-0.83 0.27-0.53 0.45-1.05 0.55-0.95 0.42-0.68
V Heat analysis B B 0.020 min B B B
Product analysis B B 0.010 min B B B
Mo Heat analysis B 0.06 max B 0.10 max B B
Product analysis B 0.07 max B 0.11 max B B
Ti Heat analysis B B B 0.05 max B B
Product analysis B B B 0.06 max B B
  • (A) A,B,C,D, E and F are classes of material used for Type 3 fasteners. Selection of a class shall be at the option of the bolt manufacturer.
  • (B) These elements are not specified or required.

ASTM A449 Mechanical Requirements

ASTM A449 Hardness Requirements for Hex Cap Screws, Bolts, and Studs

Nominal Diameter, in. Nominal Length, in. Brinell Rockwell C
Min Max Min Max
1/4 to 1, inclusive Less than 2D 253 319 25 34
2D and over . . . 319 . . . 34
Over 1 to 11/2 , inclusive Less than 3D 223 286 19 30
3D and over . . . 286 . . . 30
Over 11/2 to 3, inclusive Less than 3D 183 235 . . . . . .
3D and over . . . 235 . . . . . .
  • D = Nominal diameter or thread size

ASTM A449 Tensile Load Requirements for Coarse-Thread Hex Cap Screws, Bolts and Studs Tested Full Size

Bolt or Stud Diameter, in. Threads per in.A Stress Area,B in. 2 Tensile Load, min, lbfC Proof Load, Length Measurement Method, lbfC Alternative Proof Load, Yield Strength Method (0.2 % Offset), lbfC
1/4 20 0.0318 3 800 2 700 2 900
5/16 18 0.0524 6 300 4 450 4 800
3/8 16 0.0775 9 300 6 600 7 100
7/16 14 0.1063 12 750 9 050 9 800
1/2 13 0.1419 17 050 12 050 13 050
9/16 12 0.182 21 850 15 450 16 750
5/8 11 0.226 27 100 19 200 20 800
3/4 10 0.334 40 100 28 400 30 700
7/8 9 0.462 55 450 39 250 42 500
1 8 0.606 72 700 51 500 55 750
11/8 7 0.763 80 100 56 450 61 800
11/4 7 0.969 101 700 71 700 78 500
13/8 6 1.155 121 300 85 450 93 550
11/2 6 1.405 147 500 104 000 113 800
13/4 5 1.90 171 000 104 500 110 200
2 41/2 2.50 225 000 137 500 145 000
21/4 41/2 3.25 292 500 178 750 188 500
21/2 4 4.00 360 000 220 000 232 000
23/4 4 4.9397 443 700 271 150 286 000
3 4 5.97 537 300 328 350 346 200
  • (A) For 8 threads per in., sizes 11/8 to 11/2 in., inclusive, stresses of 105 000 psi, 74 000 psi, and 81 000 psi shall be used for calculating the values in columns 4, 5, and 6 respectively.
  • (B) The stress area is taken from ASME B1.1 which uses the equation below to calculate the values:
  • As = 0.7854[ D − (0.9743/n)]2
    • where: As = stress area,
    • D  = nominal diameter, and
    • n  = threads per in.
  • (C) Values tabulated are based on the following :
Bolt Size, in. Column 4, psi Column 5, psi Column 6, psi
1/4 to 1, incl. 120 000 85 000 92 000
11/8 to 11/2 , incl. 105 000 74 000 81 000
13/4 to 3, incl. 90 000 55 000 58 000

ASTM A449 Tensile Load Requirements for Fine-Thread Hex Cap Screws, Bolts, and Studs Tested Full Size

Bolt or Stud Diameter, in. Threads per in. Stress Area,A in. 2 Tensile Load, min, lbfB Proof Load, Length Measurement Method, lbfB Alternative Proof Load, Yield Strength Method (0.2 % Offset), min, lbfB
1/4 28 0.0364 4 350 3 100 3 500
5/16 24 0.0580 6 950 4 950 5 350
3/8 24 0.0878 10 550 7 450 8 100
7/16 20 0.1187 14 250 10 100 10 900
1/2 20 0.1599 19 200 13 600 14 700
9/16 18 0.203 24 350 17 250 18 700
5/8 18 0.256 30 700 21 750 23 500
3/4 16 0.373 44 750 31 700 34 300
7/8 14 0.509 61 100 43 250 46 800
1 12 0.663 79 550 56 350 61 000
11/8 12 0.856 89 900 63 350 69 350
11/4 12 1.073 112 650 79 400 86 900
13/8  12  1.315   138 100  97 300   106 500 
11/2 12 1.581  166 000   117 000  128 000
  • (A) See footnote B in Table 4.
  • (B) See footnote C in Table 4.

ASTM A449 Tensile Strength Requirements for Specimens Machined from Hex Cap Screws, Bolts, and Studs

Nominal Size- Threads per Inch UNC Nominal Size- Threads per Inch UNF Nominal Size- Threads per Inch 8 UN
Tensile Stress Area,AAs in.2 Tensile Stress AreaAAs in.2 Tensile Stress Area,AAs in.2
1/4 -20 0.0318  1/4 -28 0.0364 ... ...
5/16 -18 0.0524 5/16 -24 0.0580 ... ...
3/8 -16 0.0775 3/8 -24 0.0878 ... ...
7/16 -14 0.1063 7/16 -20 0.1187 ... ...
1/2 -13 0.1419 1/2 -20 0.1599 ... ...
9/16 -12 0.182 9/16 -18 0.203 ... ...
5/8 -11 0.226 5/8 -18 0.256 ... ...
3/4 -10 0.334 3/4 -16 0.373 ... ...
7/8 -9 0.462 7/8 -14 0.509 ... ...
1-8 0.606 1-12 0.663 1-8 0.606
11/8 -7 0.763 11/8 -12 0.856 11/8 -8 0.790
11/4 -7 0.969 11/4 -12 1.073 11/4 -8 1.000
13/8 -6 1.155 13/8 -12 1.315 13/8 -8 1.233
11/2 -6 1.405 11/2 -12 1.581 11/2 -8 1.492
13/4 -5 1.90 ... ... 13/4 -8 2.08
2-41/2 2.50 ... ... 2-8 2.77
21/4 -41/2 3.25 ... ... 21/4 -8 3.56
21/2 -4 4.00 ... ... 21/2 -8 4.44
23/4 -4 4.93 ... ... 23/4 -8 5.43
3-4 5.97 ... ... 3-8 6.51
31/4 -4 7.10 ... ... 31/4 -8 7.69
31/2 -4 8.33 ... ... 31/2 -8 8.96
33/4 -4 9.66 ... ... 33/4 -8 10.34
4-4 11.08 ... ... 4-8 11.81

ASTM A449 Dimensions

Nominal Diameter, in. Oversize Limit, in.A
Hot-Dip Zinc Mechanical Zinc
1/4 0.016 0.012
5/16 , 3/8 0.017 0.012
7/16 , 1/2 0.018 0.012
9/16 , 5/8 ,3/4 0.020 0.013
7/8 0.022 0.015
1.0 to 11/4 0.024 0.016
13/8 , 11/2 0.027 0.018
13/4 to 3.0, incl 0.050 0.033
  • (A) Hot-dip zinc nuts are tapped oversize after coating and mechanical zinc coated nuts are tapped oversize before coating.

ASTM A449 Bolting Surface Treatment Specifications

ASTM A449 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 A449 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 A449 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 A449 Supplementary Requirements

S1 Marking