Scope
The ASTM F3125-15 specification consolidates and covers high strength structural bolts, both Hex Head & TC Bolts, that previously fell under A325, A490, F1852 & F2280 . Bolts manufactured under this specification come in sizes from 1/2″ to 1-1/2″ inclusive. For bolts that do not fall under the diameter and length requirements for the above grades but have a similar mechanical values, see either ASTM Spec A354-BD or A449 .
3.Ordering Information
NOTE 2 —Bolts are sometimes detailed with names such as A325 HS, A325 SC, A325 X or A490 N. These names relate to connection design and bolt installation, but do not change the manufacturing requirements and are preferably not shown on bolt orders.
F3125-15 Classification
Grade Min Strength Type Head Style
A325 120 ksi 1 3 Heax Head
F1852 120 ksi 1 3 Twist-off (TC)
A490 150 ksi 1 3 Hex Head
F2280 150 ksi 1 3 Twist-off (TC)
Source: F3125-15
Heavy Hex Bolts may be ordered individually, packaged with nuts and washers or as assemblies and may be re lubricated in the field, using a stick wax or bee’s wax.
Tension Control Bolts are only shipped as an assembly of 1 bolt, 1 nut and 1 washer. TC Bolts MAY NOT BE RE LUBRICATED IN THE FIELD and may only be re lubricated by the manufacturer.
Table 1: Dimensions, Threads, Marking Matching Components
120 ksi Min Tensile 150 ksi Min Tensile
Type 1 Type 3 Type 1 Type 3
Hex Head Bolt Dimensions, ASME ᴮB18.2.6 B18.2.6 B18.2.6 B18.2.6
Hex Head Bolt Thread Fit ASME ᴮB1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A
Hex Head Bolt Grade Marking ᴬᴰA325 A325
A490 A490
Twist-Off Bolt Dimensions, ASME ᴮB18.2.6 B18.2.6 B18.2.6 B18.2.6
Twist-Off Bolt Thread Fit ASME ᴮB1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A B1.1 UNC 2A
Twist-Off Bolt Grade Marking ᴬᴰA325TC A325TC
A490TC A490TC
Twist-Off Bolt Alt Marking ᴬᶜA325 A325
A490 A490
Recommended Plain Nut A563 DH A563 DH3 A563 DH A563 DH3
Recommended Alternative Nut DH3, D, C, C3 C3
Recommended Coated Nut A563 DH A563 DH3 A563 DH A563 DH3
Flat, Bevel or Thick Washer F436-1 F436-3 F436-1 F436-3
Source: ASTM F3125-15
Table 2: Chemical Requirments
Heat Analysis 120 ksi Min, Grade A325 & F1852 150 ksi Min, Grade A490 & F2280
Type 1 Type 3 Type 1 Type 3
Carbon or Alloy ᴰ with or without Boron Composition A Composition B Based on Corrosion Index ᴱ Alloy ᴰ Steel with or without Boron Based On Corrosion Index ᴱ
Carbon 0.30 - 0.52 0.33 - 0.40 0.38 - 0.48 0.3 - 0.52 max 0.3 - 0.48 ᴬ 0.3 - 0.53
Manganese 0.60 min 0.90 - 1.20 0.70 - 0.90 0.6 min 0.6 min 0.6 min
Phosphorus max 0.035 0.035 0.035 0.035 0.035 0.035
Sulfur max 0.04 0.04 0.04 0.04 0.04 0.04
Silicon 0.15 - 0.30 0.15 - 0.30 0.3 - 0.5 ʙ ʙ ʙ
Boron 0.003 max ʙ ʙ ʙ 0.003 max ʙ
Copper ʙ 0.25 - 0.45 0.2 - 0.4 0.2 - 0.60 ʙ ʙ 0.2 - 0.6 ᴱ
Nickel ʙ 0.25 - 0.45 0.5 - 0.8 0.20 ʙ,c min ʙ 0.2 ᴱ,ᶠmin
Chromium ʙ 0.45 - 0.65 0.5 - 0.75 0.45 ʙ min ʙ 0.45 ᴱ min
Vanadium ʙ ʙ ʙ ʙ ʙ ʙ
Molybdenum ʙ ʙ 0.063 max 0.10 ʙ,c min ʙ 0.1 ᴱ,ᶠ min
Titanium ʙ ʙ ʙ ʙ ʙ ʙ
Source ASTM F3125-15
Table 3: Number of Tests and Test Method or Criteria
Table 3 Number of Tests & Test Method or Criteria
All Grades, Types, Styles Sample Size Per Lot Test Method Notes
Tensile Strength F1470 F606/F606M Wedge or Axial Full Size. Machined See 8.1.1
Proof Load F1470 F606/F606M Method 1 or 2 optional. See 8.1.2
Hardness F1470 F606/F606M
Dimensions and Thread Fit ASME B18.18 ASME B18.2.6 B1.1 2A
Surface Discontinuities F1470 F788
Coating Weight/Thickness F1470 ᴮ Product Specification
150 ksi grades all types/styles
Magnetic Partical F1470 F788 Guide E709 of Practice E1444/E1444M
Carburization/Decarburization At least 1 F2328
All Twist Off Assemblies
Fastener Tension F1470 This Standard
Rotational Capacity ᴬ F1470 Annex A2
Source: ASTM F3125-15
Table 4: Tensile Strength Requirements for Bolts Tested Full Size
120 ksi - A325 (Hex) & F1852 (Twist-Off) 150 ksi - A490 (Hex) & F2280 (Twist-Off)
Diameter Stress Area in ² Tensile min lbf Proof Load min lbf Proof Load min lbf Tensile min lbf Tensile max lbf Proof Load min lbf Proof Load min
1/2" 0.142 17,050 12,050 13,050 21,300 24,600 17,050 18,500
5/8" 0.226 27,100 19,200 20,800 33,900 39,100 27,100 29,400
3/4" 0.334 40,100 28,400 30,700 50,100 57,800 40,100 43,400
7/8" 0.462 55,450 39,250 42,500 69,300 79,950 55,450 60,100
1" 0.606 72,700 51,500 55,700 90,900 104,850 72,700 78,800
1-1/8" 0.763 91,600 64,900 70,250 114,450 132,000 91,600 99,200
1-1/4" 0.969 116,300 82,400 89,200 145,350 167,650 116,300 126,000
1-3/8" 1.155 138,600 98,200 106,300 173,250 199,850 138,600 150,200
1-1/2" 1.105 168,600 119,500 129,300 210,750 243,100 168,600 182,600
Above values based on 120,000psi 85,000psi 92,000psi 150,000psi 173,000psi 120,000psi 130,000psi
Source: ASTM F3125-15
Table 5: Tensile Strength Requirements For Specimens Machined from Bolts
Tensile min Tensile max Yield min Elongation in 4D min Reduction of Area, min
120 ksi A325 & F1852 120000 psi NA 92,000 psi 0.14 0.35
150 ksi A490 & F2280 150000 psi 173,000 psi 130,000 psi 0.14 0.4
Source: ASTM F3125-15
Table 6 Hardness Requirments for Bolts
120 ksi Tensile, Grde A325 & F1852 150 ksi Tensile, Grade A490 & F2280
Brinell HB Rockwell HRC Brinell HB Rockwell HRC
Diameter Length Min Max Min Max Min Max Min Max
≤ 1" Less than 2 x Diameter 253 319 25 34 311 352 33 38
≤ 1" 2 x Diameter and longer - 319 - 34 - 352 - 38
Over 1" Less than 3 x Diameter 253 319 25 34 311 352 33 38
Over 1" 3 x Diameter and Longer - 319 - 34 - 352 - 38
Source: ASTM F3125-15
F3125-15 Table 7 Twist-Off Style Assembly Installation Tension Test (Minimum Tension, lbf)
Diameter F1852 F2280
1/2" 12,550 15,650
5/8" 19,900 24,900
3/4" 29,450 36,800
7/8" 40,750 50,950
1" 53,450 66,800
1-1/8" 67,350 84,100
1-1/4" 85,500 106,850
Source: ASTM F3125-15
ASTM F3125-15 approved Jan. 1st, 2015.
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