Heavy Hex Bolts
SeveralASTM specificationsrequire a hex head that is larger than a standard (finished) hex head. These specifications include: A193, A320and A307B. Although A325 andA490bolts also require a heavy hex head, please refer to Structural Boltsfor dimensional specifications, since these bolts have shorter thread lengths than standard heavy hex bolts.
Manufacturing
Taida Bolt manufactures heavy hex bolts from 1/2" diameter through 2-1/2" diameter in most ASTM, AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head dimensions or bolt heads with your company's name and/or logo.
Standard: ASTM A325/A563/F436
Dia.: 1/2"-1 1/2";
Length:1 1/4"-8";
Surface treatment: Plain ,Black oxygenation, HDG
Standard Thread Lengths
Bolt lengths < 6": Thread length = (2 X diameter) + 1/4"
Bolt lengths > 6": Thread length = (2 X diameter) + 1/2"
Dimensions
Bolt Diameter
|
D
|
F
|
C
|
H
|
Body Diameter
|
Width Across Flats
|
Width Across Corners
|
Height
|
Max
|
Basic
|
Max
|
Min
|
Max
|
Min
|
Basic
|
Max
|
Min
|
1/2
|
0.515
|
7/8
|
0.875
|
0.850
|
1.010
|
0.969
|
11/32
|
0.364
|
0.302
|
5/8
|
0.642
|
1-1/16
|
1.062
|
1.031
|
1.227
|
1.175
|
27/64
|
0.444
|
0.378
|
3/4
|
0.768
|
1-1/4
|
1.250
|
1.212
|
1.443
|
1.383
|
1/2
|
0.524
|
0.455
|
7/8
|
0.895
|
1-7/16
|
1.438
|
1.394
|
1.660
|
1.589
|
37/64
|
0.604
|
0.531
|
1
|
1.022
|
1-5/8
|
1.625
|
1.575
|
1.876
|
1.796
|
43/64
|
0.700
|
0.591
|
1-1/8
|
1.149
|
1-13/16
|
1.812
|
1.756
|
2.093
|
2.002
|
3/4
|
0.780
|
0.658
|
1-1/4
|
1.277
|
2
|
2.00
|
1.938
|
2.309
|
2.209
|
27/32
|
0.876
|
0.749
|
1-3/8
|
1.404
|
2-3/16
|
2.188
|
2.119
|
2.526
|
2.416
|
29/32
|
0.940
|
0.810
|
1-1/2
|
1.531
|
2-3/8
|
2.375
|
2.300
|
2.742
|
2.622
|
1
|
1.036
|
0.902
|
1-3/4
|
1.785
|
2-3/4
|
2.750
|
2.662
|
3.175
|
3.035
|
1-5/32
|
1.196
|
1.054
|
2
|
2.039
|
3-1/8
|
3.125
|
3.025
|
3.608
|
3.449
|
1-11/32
|
1.388
|
1.175
|
2-1/4
|
2.305
|
3-1/2
|
3.500
|
3.388
|
4.041
|
3.862
|
1-1/2
|
1.548
|
1.327
|
2-1/2
|
2.559
|
3-7/8
|
3.875
|
3.750
|
4.474
|
4.275
|
1-21/32
|
1.708
|
1.479
|
Dimensions per ASME B18.2.1 1996
Scope
The ASTM A325 specification covers high strength heavy hex structural bolts from ½” diameter through 1-1/2” diameter. These bolts are intended for use in structural connections and therefore have shorter thread lengths than standard hex bolts. Refer to the Structural Bolts page of our site for thread lengths and other related dimensions.
This specification is applicable to heavy hex structural bolts only. For bolts of other configurations and thread lengths with similar mechanical properties, see Specification A 449.
Bolts for general applications, including anchor bolts, are covered by Specification A 449. Also refer to Specification A 449 for quenched and tempered steel bolts and studs with diameters greater than 1-1/2" but with similar mechanical properties.
Types
TYPE 1
|
Medium carbon, carbon boron, or medium carbon alloy steel.
|
TYPE 2
|
Withdrawn November 1991.
|
TYPE 3
|
Weathering steel.
|
|
T
|
Fully threaded A325. (Restricted to 4 times the diameter in length)
|
M
|
Metric A325.
|
Connection Types
Mechanical Properties
Size
|
Tensile, ksi
|
Yield, ksi
|
Elong. %, min
|
RA %, min
|
1/2 - 1
|
120 min
|
92 min
|
14
|
35
|
1-1/8 - 1-1/2
|
105 min
|
81 min
|
14
|
35
|
Recommended Nuts and Washers
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
|
Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A325 heavy hex structural bolts. The ASTM A563 Nut
|
|