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A307 Hex Bolt, Galvanized

ASTM A307 Grade A hex bolts are common fasteners manufactured from low carbon steel. Dimensional specifications are governed by ASME B18.2.1. Grade marking consists of both the grade symbol "307A" and the manufacturer's identification mark. Inch series fasteners meeting ASTM A307 Grade A specifications are common/economical fasteners used for general applications. These bolts have a finished pattern head, whereas A307 Grade B bolts have a heavy pattern head. A307 hex bolts are available in hot dip galvanized finish, which provides a corrosion resistant zinc coating.

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Governing Standards
Mechanical Properties
Chemical Properties
Dimensional Specifications

Dimensional Specifications

Dimensional SpecificationsA307

Per ASME B18.2.1-2012
Nominal Diameter		UNC	UNF	E		F			G		H			LT
				Body Diameter		Width Across Flats			Width Across Corners		Head Height			Thread Length
				Max	Min	Basic	Max	Min	Max	Min	Basic	Max	Min	Lengths up to 6"	Lengths > 6"
1/4	0.2500	20	28	0.2500	0.2405	7/16	0.4380	0.4280	0.5050	0.4880	5/32	0.1630	0.1500	0.7500	1.0000
5/16	0.3125	18	24	0.3125	0.3065	1/2	0.5000	0.4890	0.5770	0.5570	13/64	0.2110	0.1950	0.8750	1.1250
3/8	0.3750	16	24	0.3750	0.3690	9/16	0.5620	0.5510	0.6500	0.6280	15/64	0.2430	0.2260	1.0000	1.2500
7/16	0.4375	14	20	0.4375	0.4305	5/8	0.6250	0.6120	0.7220	0.6980	9/32	0.2910	0.2720	1.1250	1.3750
1/2	0.5000	13	20	0.5000	0.4930	3/4	0.7500	0.7360	0.8660	0.8400	5/16	0.3230	0.3020	1.2500	1.5000
9/16	0.5625	12	18	0.5625	0.5545	13/16	0.8120	0.7980	0.9380	0.9100	23/64	0.3710	0.3480	1.3750	1.6250
5/8	0.6250	11	18	0.6250	0.6170	15/16	0.9380	0.9220	1.0830	1.0510	25/64	0.4030	0.3780	1.5000	1.7500
3/4	0.7500	10	16	0.7500	0.7410	1 1/8	1.1250	1.1000	1.2990	1.2540	15/32	0.4830	0.4550	1.7500	2.0000
7/8	0.8750	9	14	0.8750	0.8660	1 5/16	1.3120	1.2850	1.5160	1.4650	35/64	0.5630	0.5310	2.0000	2.2500
1	1.0000	8	14	1.0000	0.9900	1 1/2	1.5000	1.4690	1.7320	1.6750	39/64	0.6270	0.5910	2.2500	2.5000
1 1/8	1.1250	7	12	1.1250	1.1140	1 11/16	1.6880	1.6310	1.9490	1.8590	11/16	0.7180	0.6580	2.5000	2.7500
1 1/4	1.2500	7	12	1.2500	1.2390	1 7/8	1.8750	1.8120	2.1650	2.0660	25/32	0.8130	0.7490	2.7500	3.0000
1 3/8	1.3750	6	12	1.3750	1.3630	2 1/16	2.0620	1.9940	2.3820	2.2730	27/32	0.8780	0.8100	3.0000	3.2500
1 1/2	1.5000	6	12	1.5000	1.4880	2 1/4	2.2500	2.1750	2.5980	2.4800	15/16	0.9740	0.9020	3.2500	3.5000

All dimensions are in inches.
Usable thread length for Hex Head Cap Screws under 6 1/4" long can be approximated by the equation THREAD LENGTH = (2 X DIAMETER) + 1/4″

A307 Hex Bolt, Galvanized

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Diameter Length Threading Item # Availability Price Quantity UOM

1/4

1/2

Full

HHG20250050

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$0.14973/EA

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1/4-20 X 1/2 A307 HEX BOLT, GALVANIZED

$0.14973/EA

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Quantity	Price
Quantity	Price
1	$0.14973/EA
780	$0.14022/EA
3110	$0.12503/EA
14000	$0.08236/EA

1/4

3/4

Full

HHG20250075

In Stock

$0.05756/EA

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1/4-20 X 3/4 A307 HEX BOLT, GALVANIZED

$0.05756/EA

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Quantity	Price
Quantity	Price
1	$0.05756/EA
610	$0.0539/EA
2430	$0.04806/EA
10930	$0.03166/EA

1/4

Full

HHG20250100

In Stock

$0.13411/EA

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1/4-20 X 1 A307 HEX BOLT, GALVANIZED

$0.13411/EA

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Quantity	Price
Quantity	Price
1	$0.13411/EA
530	$0.1256/EA
2110	$0.11199/EA
9480	$0.07377/EA

1/4

1 1/4

Partial

HHG20250125

In Stock

$0.18192/EA

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1/4-20 X 1 1/4 A307 HEX BOLT, GALVANIZED

$0.18192/EA

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Quantity	Price
Quantity	Price
1	$0.18192/EA
450	$0.17036/EA
1790	$0.1519/EA
8040	$0.10007/EA

1/4

1 1/2

Partial

HHG20250150

In Stock

$0.14052/EA

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1/4-20 X 1 1/2 A307 HEX BOLT, GALVANIZED

$0.14052/EA

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Quantity	Price
Quantity	Price
1	$0.14052/EA
390	$0.1316/EA
1560	$0.11734/EA
7000	$0.0773/EA

1/4

Partial

HHG20250200

In Stock

$0.17844/EA

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1/4-20 X 2 A307 HEX BOLT, GALVANIZED

$0.17844/EA

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Quantity	Price
Quantity	Price
1	$0.17844/EA
310	$0.16711/EA
1230	$0.149/EA
5530	$0.09816/EA

1/4

2 1/2

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HHG20250250

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$0.13545/EA

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1/4-20 X 2 1/2 A307 HEX BOLT, GALVANIZED

$0.13545/EA

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Quantity	Price
Quantity	Price
1	$0.13545/EA
260	$0.12685/EA
1020	$0.11311/EA
4590	$0.07451/EA

1/4

Partial

HHG20250300

3-5 Working Days

$0.1504/EA

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1/4-20 X 3 A307 HEX BOLT, GALVANIZED

$0.1504/EA

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3-5 Working Days

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Quantity	Price
Quantity	Price
1	$0.1504/EA
220	$0.14085/EA
870	$0.12559/EA
3920	$0.08273/EA

1/4

3 1/2

Partial

HHG20250350

In Stock

$0.25647/EA

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1/4-20 X 3 1/2 A307 HEX BOLT, GALVANIZED

$0.25647/EA

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Quantity	Price
Quantity	Price
1	$0.25647/EA
190	$0.24018/EA
760	$0.21416/EA
3410	$0.14108/EA

1/4

Partial

HHG20250400

In Stock

$0.53935/EA

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1/4-20 X 4 A307 HEX BOLT, GALVANIZED

$0.53935/EA

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Quantity	Price
Quantity	Price
1	$0.53935/EA
170	$0.5051/EA
680	$0.45037/EA
3030	$0.29668/EA

1/4

4 1/2

Partial

HHG20250450

In Stock

$0.20226/EA

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1/4-20 X 4 1/2 A307 HEX BOLT, GALVANIZED

$0.20226/EA

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In Stock

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Quantity	Price
Quantity	Price
1	$0.20226/EA
160	$0.18942/EA
610	$0.16889/EA
2710	$0.11126/EA

1/4

Partial

HHG20250500

In Stock

$0.22265/EA

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1/4-20 X 5 A307 HEX BOLT, GALVANIZED

$0.22265/EA

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In Stock

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Quantity	Price
Quantity	Price
1	$0.22265/EA
140	$0.20851/EA
550	$0.18591/EA
2470	$0.12247/EA

1/4

Partial

HHG20250600

In Stock

$1.10205/EA

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1/4-20 X 6 A307 HEX BOLT, GALVANIZED

$1.10205/EA

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Quantity	Price
Quantity	Price
1	$1.10205/EA
120	$1.03207/EA
470	$0.92024/EA
2080	$0.60622/EA

ASTM A307	Covers the mechanical and material requirements for inch series fasteners in diameters from 1/4″ through 4″, made of carbon steel having a minimum tensile strength of 60,000 psi.
ASME B18.2.1	Covers the complete general and dimensional data for multiple types of inch series square and hex bolts and screws.
ASME B1.1 UNC & UNF Class 2A	Specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads.

Low Carbon Steel			Per ASTM A307-2014
Grade A	Diameter	Bolt or Stud Length	Tensile Strength	Elongation	Core Hardness (1)
			Min psi	Min %	Rockwell
	1/4 thru 4"	Less than 3 X dia (2)	60,000	18	B69 to B100
		3 X dia and longer	60,000	18	B100

Per ASTM A307-2014
Grade A	Carbon	Manganese	Phosphorus	Sulfur
	% by heat analysis	% by heat analysis	% by heat analysis	% by heat analysis
	0.29	1.20	0.04	0.15

A307 Hex Bolt, Galvanized

Technical Data

Governing Standards

Governing StandardsA307

Mechanical Properties

Mechanical PropertiesA307

Chemical Properties

Chemical PropertiesA307

Dimensional Specifications

Dimensional SpecificationsA307

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1/4-20 X 1/2 A307 HEX BOLT, GALVANIZED

1/4-20 X 3/4 A307 HEX BOLT, GALVANIZED

1/4-20 X 1 A307 HEX BOLT, GALVANIZED

1/4-20 X 1 1/4 A307 HEX BOLT, GALVANIZED

1/4-20 X 1 1/2 A307 HEX BOLT, GALVANIZED

1/4-20 X 2 A307 HEX BOLT, GALVANIZED

1/4-20 X 2 1/2 A307 HEX BOLT, GALVANIZED

1/4-20 X 3 A307 HEX BOLT, GALVANIZED

1/4-20 X 3 1/2 A307 HEX BOLT, GALVANIZED

1/4-20 X 4 A307 HEX BOLT, GALVANIZED

1/4-20 X 4 1/2 A307 HEX BOLT, GALVANIZED

1/4-20 X 5 A307 HEX BOLT, GALVANIZED

1/4-20 X 6 A307 HEX BOLT, GALVANIZED