Grade A Heavy Hex Nut

ASTM A563 Grade A heavy hex nuts are made from carbon steel. Dimensional specifications are governed by ASME B18.2.2. Grade markings are not required for A563 Grade A heavy hex nuts, though in some cases Grade A nuts may be marked with the letter A. ASTM A563 covers standard specifications for carbon and alloy steel nuts. Heavy hex nuts provide increased bearing surface area over finished nuts.

Technical Data

Governing StandardsGrade A

ASTM A563	Covers the chemical and mechanical requirements for eight grades of carbon and alloy steel nuts for general structural and mechanical uses on bolts, studs, and other externally threaded parts.
ASME B18.2.2	Covers the complete general and dimensional data for the various types of inch series square and hex nuts, including machine screw nuts and coupling nuts.
ASME B1.1 UNC & UNF Class 2B	Specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads.

Grade A Marking
Grade A requires no material marking

Mechanical PropertiesGrade A

Carbon & Alloy Steel		Per ASTM A563-2015
Diameter	Proof Load Stress (1)		Core Hardness
	ksi		Rockwell
	Non-Zinc-Coated (2)	Zinc-Coated (2)	Min	Max
1/4" thru 4"	100	75	B68	C32

1. To determine nut proof load in pounds, multiply the appropriate nut proof load stress by the tensile stress area of the thread.
2. Non-zinc-coated nuts are nuts intended for use with externally threaded fasteners which have a plain (nonplated or noncoated) finish or have a plating or coating of insufficient thickness to necessitate overtapping the nut thread to provide assemblability. Zinc-coated nuts are nuts intended for use with externally threaded fasteners which are hot-dip zinc-coated, mechanically zinc-coated, or have a plating or coating of sufficient thickness to necessitate overtapping the nut thread to provide assemblability.

Chemical PropertiesGrade A

Per ASTM A563-2015
Grade	Material	Carbon	Manganese	Phosphorus	Sulfur
Grade	Material	% by weight	% by weight	% by weight	% by weight
A	Carbon & Alloy Steel	0.55 max	-	0.12	0.15 (1)

1. For Grade A a sulfur content of 0.23 % max is acceptable with the purchasers approval.

Dimensional SpecificationsGrade A

Per ASME B18.2.2-2015
Nominal Diameter		UNC	F			G		H
			Width Across Flats			Width Across Corners		Thickness
			Basic	Max	Min	Max	Min	Basic	Max	Min
1/4	0.250	20	1/2	0.500	0.488	0.577	0.556	15/64	0.250	0.218
5/16	0.313	18	9/16	0.562	0.546	0.650	0.220	19/64	0.314	0.280
3/8	0.375	16	11/16	0.688	0.669	0.794	0.763	23/64	0.377	0.341
7/16	0.438	14	3/4	0.750	0.728	0.866	0.830	27/64	0.441	0.403
1/2	0.500	13	7/8	0.875	0.850	1.010	0.990	31/64	0.504	0.464
9/16	0.563	12	15/16	0.938	0.909	1.083	1.037	35/64	0.568	0.526
5/8	0.625	11	1 1/16	1.062	1.031	1.227	1.175	39/64	0.631	0.587
3/4	0.750	10	1 1/4	0.250	1.212	1.443	1.382	47/64	0.758	0.710
7/8	0.875	9	1 7/16	1.438	1.394	1.660	1.589	55/64	0.885	0.833
1	1.000	8	1 5/8	1.625	1.575	1.876	1.796	63/64	1.012	0.956
1 1/8	1.125	7	1 13/16	1.812	1.756	2.093	2.002	1 7/64	1.139	1.079
1 1/4	1.250	7	2	2.000	1.380	2.309	2.209	1 7/32	1.251	1.187
1 3/8	1.375	6	2 3/16	2.188	2.119	2.526	2.416	1 11/32	1.378	1.310
1 1/2	1.500	6	2 3/8	2.375	2.300	2.742	2.622	1 15/32	1.505	1.433
1 5/8	1.625	5 1/2	2 9/16	2.562	2.481	2.959	2.828	1 19/32	1.632	1.556
1 3/4	1.750	5	2 3/4	2.750	2.662	3.175	3.035	1 23/32	1.759	1.679
1 7/8	1.875	5	2 15/16	2.938	2.844	3.392	3.242	1 27/32	1.886	1.802
2	2.000	4 1/2	3 1/8	3.125	3.025	3.608	3.449	1 31/32	2.013	1.925
2 1/4	2.250	4 1/2	3 1/2	3.500	3.388	4.041	3.862	2 13/64	2.251	2.155
2 1/2	2.500	4	3 7/8	3.875	3.750	4.474	4.275	2 29/64	2.505	2.401
2 3/4	2.750	4	4 1/4	4.250	4.112	4.907	4.688	2 45/64	2.759	2.647
3	3.000	4	4 5/8	4.625	4.475	5.340	5.102	2 61/64	3.013	2.893
3 1/4	3.250	4	5	5.000	4.838	5.774	5.515	3 3/16	3.252	3.124
3 1/2	3.500	4	5 3/8	5.375	5.200	6.207	5.928	3 7/16	3.506	3.370
3 3/4	3.750	4	5 3/4	5.750	5.562	5.562	6.341	3 11/16	3.670	3.616
4	4.000	4	6 1/8	6.125	5.925	5.925	6.755	3 15/16	4.014	3.862

All dimensions are in inches.

Grade A Heavy Hex Nut

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Diameter	Thread Pitch	Width Across Flats	Height of Nut	Item #	Availability	Price	Quantity
1/4	20	1/2	0.2344	NH2B0250000	In Stock	$0.04186/EA	EA	EA
5/16	18	9/16	0.2969	NH2B0310000	3-5 Working Days	$0.04087/EA	EA	EA
3/8	16	11/16	0.3594	NH2B0370000	In Stock	$0.08496/EA	EA	EA
1/2	13	7/8	0.4844	NH2B0500000	In Stock	$0.1947/EA	EA	EA
9/16	12	15/16	0.5469	NH2B0560000	In Stock	$0.19201/EA	EA	EA
5/8	11	1 1/16	0.6094	NH2B0620000	In Stock	$0.29676/EA	EA	EA
3/4	10	1 1/4	0.7344	NH2B0750000	In Stock	$0.4315/EA	EA	EA
7/8	9	1 7/16	0.8594	NH2B0870000	In Stock	$0.69299/EA	EA	EA
1	8	1 5/8	0.9844	NH2B1000000	In Stock	$1.43248/EA	EA	EA
1 1/8	7	1 13/16	1.1094	NH2B1120000	In Stock	$1.60729/EA	EA	EA
1 1/4	7	2	1.2188	NH2B1250000	In Stock	$2.06939/EA	EA	EA
1 3/8	6	2 3/16	1.3438	NH2B1370000	In Stock	$2.85952/EA	EA	EA
1 1/2	6	2 3/8	1.4688	NH2B1500000	In Stock	$3.27293/EA	EA	EA
1 5/8	5.5	2 9/16	1.5938	NH2B1620000	In Stock	$3.75082/EA	EA	EA
1 3/4	5	2 3/4	1.7188	NH2B1750000	In Stock	$9.75238/EA	EA	EA
2	4	3 1/8	1.9688	NH2B2000000	In Stock	$8.82257/EA	EA	EA
2 1/4	4.5	3 1/2	2.2031	NH2B2250000	In Stock	$13.17678/EA	EA	EA
2 1/2	4	3 7/8	2.4531	NH2B2500000	In Stock	$14.2531/EA	EA	EA
2 3/4	4	4 1/4	2.7031	NH2B2750000	In Stock	$29.88095/EA	EA	EA
3	4	4 5/8	2.9531	NH2B3000000	In Stock	$32.72763/EA	EA	EA
3 1/4	4	5	3.1875	NH2B3250000	In Stock	$38.89977/EA	EA	EA
3 1/2	4	5 3/8	3.6875	NH2B3750000	In Stock	$73.7606/EA	EA	EA
4	4	6 1/8	3.9375	NH2B4000000	30-50 Working Days	$109.42596/EA	EA	EA
4 1/4	4	6 1/2	4.2681	NH2B425NC	In Stock	$277.86805/EA	EA	EA
4 1/2	4	6 7/8	4.5220	NH2B450NC	In Stock	$343.88112/EA	EA	EA
5 1/2	4	8 3/8	5.5378	NH2B550NC	In Stock	$579.25577/EA	EA	EA
5 3/4	4	8 3/4	5.6248	NH2B575NC	In Stock	$685.44849/EA	EA	EA
6	4	9 1/8	6.0457	NH2B600NC	In Stock	$787.2453/EA	EA	EA

Grade A Heavy Hex Nut

Technical Data

Tab 1

Governing StandardsGrade A

Tab 2

Mechanical PropertiesGrade A

Tab 3

Chemical PropertiesGrade A

Tab 4

Dimensional SpecificationsGrade A

Product Specification

Grade

Diameter

Thread Pitch

Drive Type

Width Across Flats