SA325

Structural bolts, steel, heat treated, 120/105 ksi minimum tensile strength.

SA325

TABLE 1 : CHEMICAL REQUIREMENTS for TYPE 1 Bolts

Element /Composition, % carbon steel carbon steel
Carbon 0.28-0.55 0.28-0.55
Manganese, min 0.57 0.57
Phosphorus, max 0.048 0.040
Sulfur, max 0.058 0.045
Silicon 0.13-0.32 0.13-0.37
Alloying Element   *

* 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 °A); 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.

 

TABLE 2 Chemical Requirements for Type 3 Heavy Hex Structural Bolts A

Element

Composition,
Type 3 BoltsA
A B C
Carbon: 0.31-0.42 0.36-0.50 0.14-0.26
Manganese: 0.86-1.24 0.67-0.93 0.76-1.39
Phosphorus: 0.040 max 0.06-0.125 0.040 max
Sulfur: 0.045 max 0.045 max 0.045 max
Silicon: 0.13-0.37 0.25-0.55 0.13-0.37
Copper: 0.22-0.48 0.17-0.43 0.17-0.53
Nickel: 0.22-0.48 0.47-0.83 0.22-0.53
Chromium: 0.42-0.68 0.47-0.83 0.27-0.53
Vanadium: B B 0.010 min
Molybdenum: B 0.07 max B

(A)  A, B, C, D, E, and F are classes of material used for Type 3 bolts. Selection of a class shall be at the option of the bolt manufacturer.

(B) These elements are not specified or required.

 

TABLE 3 Hardness Requirements for Bolts

Bolt
Size
in.

Nominal Length in. Brinell Rockwell C
  Min Max Min Max

1/2 to 1, incl

Less than 2D 253 319 25 34
2D and over 319 34

11/8 to 11/2,
incl

Less than 3D 223 286 19 30
3D and over 286 30

D = Nominal diameter or thread size.

 

TABLE 4 Tensile Load Requirements for Bolts Tested Full-Size

Bolt Size, Threads per
Inch, and Series
Designation
Stress Area, A
in.
Tensile Load, B
min, lbf
Proof Load, A
Length
Measure-
ment Method
Alternative
Proof
Load, B Yield
Strength Method
1/2 —13 UNC 0.142 17 050 12 050 13 050
% -11 UNC 0.226 27 100 19 200 20 800
3/4 —10 UNC 0.334 40 100 28 400 30 700
1/2 —9 UNC 0.462 55 450 39 250 42 500
         
1-8 UNC 0.606 72 700 51 500 55 750
11/2 —7 UNC 0.763 80 100 56 450 61 800
11/4 —7 UNC 0.969 101 700 71 700 78 500
         
11/2 —6 UNC 1.155. 121 300 85 450 93 550
11/2 —6 UNC 1.405. 147 500 104 000 113 800

A The stress area is calculated as follows:

As= 0.7854 [D — (0.9743/n)2

where: As = stress area, in.2, D = nominal bolt size, and n = threads per inch.

 

B Loads tabulated are based on the following:

Bolt Size, in. Column 3 Column 4 Column 5
1/2 to 1, incl 120 000 psi 85 000 psi 92 000 psi
1 1/8 to 1 1/2, incl 105 000 psi 74 000 psi 81 000 psi

 

TABLE 5 Tensile Strength Requirements for Specmens Macined from Bolts

Bolt Diameter, in.

Tensile Strength, min Yield Strength,min Elongation in 4D, Reduction of Area,
psi (MPa) psi (MPa) min, % min, %
1/2 to 1, incl 120 000 (825) 92 000 (635) 14 35
Over 1 to 1 1/2 105 000 (725) 81 000 (560) 14 35

 

A325 Recommended Hardware

Nuts Washers
Type 1 Type 3

Type 1

Type 3

Plain Galvanized Plain
A563C, C3, D, DH, DH3 A563DH A563C3, DH3 F436-1 F436-3