Nut Specifications

Nuts are essential components in threaded assemblies, providing clamping force, preload retention, and vibration resistance. At TUHU Fasteners, we supply a wide range of products—including hex nuts, heavy hex nuts, lock nuts, flange nuts, and coupling nuts—manufactured to meet ASTM, SAE, DIN, and ISO standards. This page provides detailed nut specifications, including standard dimensions, thread types (UNC/UNF/Metric), material grades, mechanical properties, and chemical compositions for industrial use. Click the button below to view our full range of nut products.

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Thread type: M / UNC / UNF

Diameter (mm)	Pitch (mm)	Diameter (mm)	Pitch (mm)
M6	1	M24	3
M8	1.25	M24	2
M8	1	M27	3
M10	1.5	M27	2
	1.25	M30	3.5
	1	M30	2
M12	1.75	M33	3.5
	1.25	M33	2
	1.5	M36	4
M14	2	M36	3
M14	1.5	M42	4.5
M16	2	M42	3
M16	1.5	M45	4.5
M18	2.5	M48	5
	2	M48	3
	1.5	M52	5
M20	2.5	M56	5.5
	2	M56	4
	1.5
M22	2.5
	2
	1.5

Diameter (Inch)	Pitch (Threads Per Inch)	Diameter (Inch)	Pitch (Threads Per Inch)
1/4"	20UNC	7/8"	9UNC
1/4"	28UNF	7/8"	14UNF
5/16"	18UNC	1"	8UNC
5/16"	24UNF	1"	12UNF
3/8"	16UNC	1-1/8"	7UNC
3/8"	24UNF	1-1/8"	8UNF
7/16"	14UNC	1-1/4"	7UNC
7/16"	20UNF	1-1/4"	8UNF
1/2"	13UNC	1-3/8"	6UNC
1/2"	20UNF	1-3/8"	8UNF
9/16"	12UNC	1-1/2"	6UNC
9/16"	18UNF	1-1/2"	8UNF
5/8"	11UNC	1-3/4"	5UNC
5/8"	18UNF	1-3/4"	8UNF
3/4"	10UNC
3/4"	16UNF

Nut Dimension Standard

Nut type	Nut Standard
Hex nut	ASTM B18.2.2, DIN934
Heavy hex nut	ASTM B18.2.2, DIN6915
Square nut	ASME/ANSI B18.2.2; DIN557, DIN562
Hex flange nut	ASTM B18.2.2, ASTM B18.16.4, DIN6923
Hex nylon insert nut	ASME/ANSI B18.16.6; DIN985, DIN982
All metal lock nut	ASME B18.16.6, DIN980V, DIN980M, DIN6925
Castle nut	ASME/ANSI B18.2.2; DIN935
Cap nut	SAE J483, DIN1587, DIN917
Clip nut	QC 312
Hex coupling nut	ASTM B18.2.2, DIN6334

A563 Nut Grade Specification

Standard for Nut	Grade	Hardness	Dimensional style of nut	Nominal nut size	Proof Load Stress ksi
				in.	Non-Zinc coated Nuts	Zinc coated Nuts
A563	A	HRB68-HRC32	Hex	1/4 to 1-1/2	90	68
			Heavy hex	1/4 to 4	100	75
			Hex thick	1/4 to 1-1/2	100	75
	B	HRB69-HRC32	Hex	1/4 to 1	120	90
			Hex	1-1/8 to 1-1/2	105	79
			Heavy hex and hex thick	1/4 to 1	133	100
			Heavy hex and hex thick	1-1/8 to 1-1/2	116	87
	C / C3	HRB78-HRC38	Heavy hex	1/4 to 4	144	144
	D	HRB84-HRC38	Hex	1/4 to 1-1/2	135	135
			Heavy hex	1/4 to 4	150	150
			Hex thick	1/4 to 1-1/2	150	150
	DH	HRC24-HRC38	Hex	1/4 to 1-1/2	150	150
			Heavy hex	1/4 to 4	175	150
			Hex thick	1/4 to 1-1/2	175	175
	DH3	HRC24-HRC38	Heavy hex	1/4 to 4	175	150

A563 Chemical Properties

Element		Grades O, A, B, C			D**		DH**
Carbon		0.55% max			0.55% max		0.20 - 0.55%
Manganese, min		-			0.30%		0.60%
Phosphorus, max		0.12%			0.04%		0.04%
Sulfur, max		0.15%*			0.05%		0.05%
* For grades O, A and B a sulfur content of 0.23% max is acceptable with the purchasers approval
** For grades D and DH a sulfur content of 0.05 - 0.15% is acceptable provided the manganese is 1.35% min
Element	Classes for Grade C3*							DH3
Element	A	B	C	D	E	F	N	DH3
Carbon	0.33 - 0.40%	0.38 - 0.48%	0.15 - 0.25%	0.15 - 0.25%	0.20 - 0.25%	0.20 - 0.25%	-	0.20 - 0.53%
Manganese	0.90 - 1.20%	0.70 - 0.90%	0.80 - 1.35%	0.40 - 1.20%	0.60 - 1.00%	0.90 - 1.20%	-	0.40% min
Phosphorus	0.040% max	0.06 - 0.12%	0.035% max	0.040% max	0.040% max	0.040% max	0.07 - 0.15%	0.046% max
Sulfur, max	0.050%	0.050%	0.040%	0.050%	0.040%	0.040%	0.050%	0.050%
Silicon	0.15 - 0.35%	0.30 - 0.50%	0.15 - 0.35%	0.25 - 0.50%	0.15 - 0.35%	0.15 - 0.35%	0.20 - 0.90%
Copper	0.25 - 0.45%	0.20 - 0.40%	0.20 - 0.50%	0.30 - 0.50%	0.30 - 0.60%	0.20 - 0.40%	0.25 - 0.55%	0.20% min
Nickel	0.25 - 0.45%	0.50 - 0.80%	0.25 - 0.50%	0.50 - 0.80%	0.30 - 0.60%	0.20 - 0.40%	1.00% max	0.20% min**
Chromium	0.45 - 0.65%	0.50 - 0.75%	0.30 - 0.50%	0.50 - 1.00%	0.60 - 0.90%	0.45 - 0.65%	0.30 - 1.25%	0.45% min
Vanadium	-	-	0.020% min	-	-	-	-	-
Molybdenum	-	0.06% max	-	0.10% max	-	-	-	0.15% min**
Titanium	-	-	-	0.05% max	-	-	-	-
* Selection of a class shall be at the option of the manufacturer
** Nickel or Molybdenum may be used.

A194 Nut Grade Specification

Standard for Nut	Grade	Hardness	Dimensional style of nut	Nominal nut size	Proof Load Stress ksi		Tempering Temp	Hardness Rockwell
				in.	Non-Zinc coated Nuts	Zinc coated Nuts	°F	min	max
A194	2		Heavy hex	1/4 to 4	150	150	0	159	352
	2H	≦1-1/2: 248-352, >1-1/2 : 212-352	Hex	1/4 to 1-1/2	150	150	850	C24	C38
	2H	≦1-1/2: 248-352, >1-1/2 : 212-352	Heavy hex	1/4 to 4	175	175	850	C24	C38
	2HM	HRB159-235	Hex	1/4 to 1-1/2	135	135	1150	159	237
	2HM	HRB159-235	Heavy hex	1/4 to 4	150	150	1150	159	237
	4	248-327	Hex	1/4 to 1-1/2	150	150	1100	C24	C38
	4	248-327	Heavy hex	1/4 to 4	175	175	1100	C24	C38
	7	248-327	Hex	1/4 to 1-1/2	150	150	1100	C24	C38
	7	248-327	Heavy hex	1/4 to 4	175	175	1100	C24	C38
	7M	HRB159-235	Hex	1/4 to 1-1/2	135	135	1150	159	237
	7M	HRB159-235	Heavy hex	1/4 to 4	150	150	1150	159	237
	8	126-300	Hex	1/4 to 1-1/2	75	75	-	126	300
	8	126-300	Heavy hex	1/4 to 4	80	80	-	126	300
	8M	126-300	Hex	1/4 to 1-1/2	75	75	-	126	300
	8M	126-300	Heavy hex	1/4 to 4	80	80	-	126	300

A194 Chemical Properties

Element	2, 2H, and 2HM	4	7 and 7M (AISI 4140)	8 (AISI 304)	8M (AISI 316)
Carbon	0.40% min	0.40 - 0.50%	0.37 - 0.49%	0.08% max	0.08% max
Manganese	1.00% max	0.70 - 0.90%	0.65 - 1.10%	2.00% max	2.00% max
Phosphorus, max	0.040%	0.035%	0.035%	0.045%	0.045%
Sulfur, max	0.050%	0.040%	0.040%	0.030%	0.030%
Silicon	0.40% max	0.15 - 0.35%	0.15 - 0.35%	1.00% max	1.00% max
Chromium	-	-	0.75 - 1.20%	18.0 - 20.0%	16.0 - 18.0%
Nickel	-	-	-	8.0 - 11.0%	10.0 - 14.0%
Molybdenum	-	0.20 - 0.30%	0.15 - 0.25%	-	2.00 - 3.00%

SAE J995 & ISO 898-2 2009 Nut Grade Specification

Standard for Nut	Grade	Hardness	Dimensional style of nut	Nominal nut size	Proof Load Stress ksi
				in.	Non-Zinc coated Nuts	Zinc coated Nuts
SAE J995	2	HRC32 max	Hex	1/4 to 1-1/2	90	90
	5	HRC32 max	Hex	1/4 to 1	120	120
	5	HRC32 max	Hex	1-1/8 to 1-1/2	105	105
	8	24-32HRC	Hex	1/4 to 5/8	150	150
		26-34HRC		3/4 to 1
		26-36HRC		1-1/8 to 1-1/2
ISO 898-2 2009 (DIN934)	4	Over M16 117-302HV				510MPa
	6	Up to M16 15-302HV，over M16 170-302HV				600-720MPa
	8	M4 180-302，up to M16 200-302(HRB94-31.5)， up to M39 233-353HV				800-920MPa
	8					800-920MPa
	10	272-353HV				1040-1060MPa
	12	272-353HV				1140-1170MPa

Nut FAQ

What standards are typically used for industrial nuts?

Most industrial nuts conform to ASTM, SAE, ISO, or DIN standards depending on application and region. Common examples include ASTM A563, A194, and SAE J995.

How do I know which grade is right for my application?

The appropriate grade depends on factors like load requirements, operating environment, and material compatibility. Always refer to engineering specifications or consult a supplier for guidance.

Are surface coatings available for corrosion protection?

Yes. Zinc plating, hot-dip galvanizing, and other surface treatments are commonly offered to improve corrosion resistance in different environments.

Need Help Matching Nuts to Your Bolts or Structural Hardware?

Contact our team at sales@tuhufasteners.com with your requirements. We’ll help you select the best-fit nut based on your application and industry standards.

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