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Grade 8 Hex Cap Screw, Plated

SAE J429 Grade 8 hex head cap screws are common, high-strength fasteners manufactured from heat-treated medium carbon alloy steel, quenched and tempered. Grade 8 cap screws are available in diameters from 1/4" through 1 1/2" inclusive. Dimensional specifications are governed by ASME B18.2.1. Grade marking consists of 6 radial lines. Inch series fasteners meeting SAE J429 Grade 8 specifications are general use fasteners commonly used in automotive and construction related industries. These fasteners are available in yellow zinc plated finish. Zinc plating sacrifices itself, corroding before the base material, offering added corrosion resistance.

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Governing Standards
Mechanical Properties
Chemical Properties
Dimensional Specifications

Chemical Properties

Chemical PropertiesGrade 8

Per SAE J429 2014-05
Grade	Material	Carbon	Phosphorus	Sulfur	Boron	Tempering Temperature
Grade	Material	% by weight	% by weight	% by weight	% by weight	Min
8	Carbon (1) Steel with additives (e.g. Boron (2) or Cr, or Mn)	0.25-0.55	0.025 max	0.025 max (5)	0.003	800F
	Medium Carbon Steel	0.25-0.55	0.025 max	0.025 max (5)		800F
	Alloy Steel (3,4)	0.25-0.55	0.025 max (6)	0.025 max (6)		800F

1. For steels of these types there shall be sufficient hardenability to ensure a microsructure consisting of approximately 90% martensite (refer Table 3) in the core of threaded sections of the fasteners after hardening and quenching and before tempering.
2. When boron is added the limits shall be 0.0005 % to 0.003 %.
3. Alloy steel shall contain at least one of the following elements in the minimum quantity given: chromium 0.30 %, nickel 0.30 %, molybdenum 0.20 %, vanadium 0.10 %, manganese 1.65%. Where elements are specified in combinations of two, three, four, or five and have alloy contents less than those given above, the limit value to be applied for steel class determination is 70 % of the sum of the individual limit values shown above for the two, three, four or five elements concerned.
4. For steels of these types there shall be sufficient hardenability to ensure a microsructure consisting of approximately 90% martensite (refer Table 3) in the core of threaded sections of the fasteners after hardening and quenching and before tempering.
5. For studs only, sulfur content may be 0.13% maximum.
6. Alloy steel used to make fasteners by hot forging or machining may have a maximum content by weight of 0.030% P (phosphorus) and 0.040% S (sulfur).

Dimensional Specifications

Dimensional SpecificationsGrade 8

Per ASME B18.2.1-2012
Nominal Diameter		UNC	UNF	E		F			G		H			J	LT		Y
				Body Diameter		Width Across Flats			Width Across Corners		Head Height			Wrench Height	Thread Length		Transition Length
				Max	Min	Basic	Max	Min	Max	Min	Basic	Max	Min	Min	Lengths up to 6"	Lengths > 6"	Max
1/4	0.25	20	28	0.25	0.2405	7/16	0.438	0.428	0.505	0.488	5/32	0.163	0.15	0.106	0.75	1	0.25
5/16	0.3125	18	24	0.3125	0.3065	1/2	0.5	0.489	0.577	0.557	13/64	0.211	0.195	0.14	0.875	1.125	0.275
3/8	0.375	16	24	0.375	0.369	9/16	0.562	0.551	0.65	0.628	15/64	0.243	0.226	0.16	1	1.25	0.312
7/16	0.4375	14	20	0.4375	0.4305	5/8	0.625	0.612	0.722	0.698	9/32	0.291	0.272	0.195	1.125	1.375	0.357
1/2	0.5	13	20	0.5	0.493	3/4	0.75	0.736	0.866	0.84	5/16	0.323	0.302	0.215	1.25	1.5	0.385
9/16	0.5625	12	18	0.5625	0.5545	13/16	0.812	0.798	0.938	0.91	23/64	0.371	0.348	0.25	1.375	1.625	0.417
5/8	0.625	11	18	0.625	0.617	15/16	0.938	0.922	1.083	1.051	25/64	0.403	0.378	0.269	1.5	1.75	0.455
3/4	0.75	10	16	0.75	0.741	1 1/8	1.125	1.1	1.299	1.254	15/32	0.483	0.455	0.324	1.75	2	0.5
7/8	0.875	9	14	0.875	0.866	1 5/16	1.312	1.285	1.516	1.465	35/64	0.563	0.531	0.378	2	2.25	0.556
1	1	8	14	1	0.99	1 1/2	1.5	1.469	1.732	1.675	39/64	0.627	0.591	0.416	2.25	2.5	0.625
1 1/8	1.125	7	12	1.125	1.114	1 11/16	1.688	1.631	1.949	1.859	11/16	0.718	0.658	0.461	2.5	2.75	0.714
1 1/4	1.25	7	12	1.25	1.239	1 7/8	1.875	1.812	2.165	2.066	25/32	0.813	0.749	0.53	2.75	3	0.714
1 3/8	1.375	6	12	1.375	1.363	2 1/16	2.062	1.994	2.382	2.273	27/32	0.878	0.81	0.569	3	3.25	0.833
1 1/2	1.5	6	12	1.5	1.488	2 1/4	2.25	2.175	2.598	2.48	15/16	0.974	0.902	0.64	3.25	3.5	0.833

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″

Grade 8 Hex Cap Screw, Plated

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1/4

3/4

Full

HHP80250075

In Stock

$0.12465/EA

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1/4-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.12465/EA

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Quantity	Price
Quantity	Price
1	$0.12465/ EA
610	$0.11674/ EA
2440	$0.10409/ EA
10980	$0.06857/ EA

1/4

3/4

Full

HHP80250075NF

In Stock

$0.25249/EA

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1/4-28 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.25249/EA

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Quantity	Price
Quantity	Price
1	$0.25249/ EA
610	$0.23646/ EA
2440	$0.21084/ EA
10980	$0.13889/ EA

5/16

3/4

Full

HHP80310075

In Stock

$0.21639/EA

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5/16-18 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.21639/EA

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Quantity	Price
Quantity	Price
1	$0.21639/ EA
380	$0.20272/ EA
1500	$0.18053/ EA
6750	$0.11963/ EA

5/16

3/4

Full

HHP80310075NF

In Stock

$0.40732/EA

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5/16-24 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.40732/EA

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Quantity	Price
Quantity	Price
1	$0.40732/ EA
380	$0.38158/ EA
1500	$0.33982/ EA
6750	$0.22519/ EA

3/8

3/4

Full

HHP80370075

In Stock

$0.23877/EA

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3/8-16 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.23877/EA

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Quantity	Price
Quantity	Price
1	$0.23877/ EA
260	$0.22419/ EA
1020	$0.20047/ EA
4560	$0.13273/ EA

3/8

3/4

Full

HHP80370075NF

In Stock

$0.16953/EA

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3/8-24 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.16953/EA

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Quantity	Price
Quantity	Price
1	$0.16953/ EA
260	$0.15918/ EA
1020	$0.14233/ EA
4560	$0.09424/ EA

7/16

3/4

Full

HHP80430075

In Stock

$0.5148/EA

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7/16-14 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.5148/EA

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In Stock

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Quantity	Price
Quantity	Price
1	$0.5148/ EA
190	$0.48292/ EA
750	$0.42859/ EA
3350	$0.28756/ EA

7/16

3/4

Full

HHP80430075NF

In Stock

$0.52121/EA

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7/16-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.52121/EA

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In Stock

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Quantity	Price
Quantity	Price
1	$0.52121/ EA
190	$0.48893/ EA
750	$0.43392/ EA
3350	$0.29114/ EA

1/2

3/4

Full

HHP80500075

In Stock

$0.47097/EA

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1/2-13 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$0.47097/EA

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Quantity	Price
Quantity	Price
1	$0.47097/ EA
130	$0.44211/ EA
490	$0.39195/ EA
2190	$0.26408/ EA

1/2

3/4

Full

HHP80500075NF

In Stock

$1.10687/EA

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1/2-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

$1.10687/EA

Qty

In Stock

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Quantity	Price
Quantity	Price
1	$1.10687/ EA
130	$1.03904/ EA
490	$0.92116/ EA
2190	$0.62065/ EA

SAE J429	Covers the mechanical and material requirements for inch series fasteners used in automotive and related industries in diameters through 1-1/2″.
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.

Medium Carbon Steel, Heat Treated, Quenched and Tempered				Per SAE J429 2014-05
Diameter	Full Size Proof Load	Yield Strength	Tensile Strength	Elongation	Reduction in Area	Core Hardness
Diameter	psi	Min psi	Min psi	Min %	Min %	Rockwell
1/4 thru 1 1/2"	120,000	130,000	150,000	12	35	C33 to C39

Grade 8 Hex Cap Screw, Plated

Technical Data

Governing Standards

Governing StandardsGrade 8

Mechanical Properties

Mechanical PropertiesGrade 8

Chemical Properties

Chemical PropertiesGrade 8

Dimensional Specifications

Dimensional SpecificationsGrade 8

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1/4-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

1/4-28 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

5/16-18 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

5/16-24 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

3/8-16 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

3/8-24 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

7/16-14 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

7/16-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

1/2-13 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED

1/2-20 X 3/4 J429 GRADE 8 HEX CAP SCREW, PLATED