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Heavy Hex Nuts

Manufacturer, Exporter & Supplier of Heavy Hex Nut

Heavy Hex Nuts Manufacturer for Structural & Industrial Applications

Heavy hex nuts are high-strength fastening components designed with a larger width across flats and increased thickness compared to standard hex nuts. This geometry provides superior load distribution and higher torque resistance, making them essential in structural steel assemblies, oil & gas infrastructure, power generation equipment, and heavy machinery installations. These nuts are commonly manufactured in compliance with ASTM A563, ASTM A194, DIN 934, and ISO metric standards depending on application requirements.

Carbon Steel Heavy Hex Nuts Supplier
Inconel Heavy Hex Nuts Manufacturer
Stainless Steel Heavy Hex Nuts Exporter

In critical bolting systems where vibration, dynamic loads, and thermal expansion are present, heavy hex nuts ensure joint integrity and long-term fastening reliability. They are engineered for compatibility with high-tensile bolts used in bridges, industrial plants, and pressure systems.

KK Fasteners supplies heavy hex nuts to global industrial clients with full material traceability, consistent dimensional accuracy, and compliance with international fastening standards used across engineering sectors worldwide.

Technical Heavy Hex Nuts Specifications​

Material Options Carbon Steel, Alloy Steel, Stainless Steel (SS 304, SS 316), Duplex Steel
Grades ASTM A563 Grade A, C, DH; ASTM A194 2H, 8, 8M
Size Range M6 to M100 / 1/4” to 4”
Thread Type Metric (ISO), UNC, UNF
Standards ASTM A563, ASTM A194, DIN 934, ISO 4032, BS 1768
Surface Finish Black Oxide, Hot Dip Galvanized (HDG), Zinc Plated, PTFE Coated
Type Variants Heavy Hex Nut, Heavy Hex Jam Nut
Hardness Up to 35–45 HRC (depending on grade)
Tensile Strength Up to 1200 MPa (material dependent)

Heavy Hex Nuts Dimension Chart (ANSI/ASME B18.2.2)

Nominal or Basic Major Diameter of Thread

 		 Width Across Flats (F)

 Width Across Corners (G) Thickness of Hex Nuts (H) 
Basic Max Min  Max  Min Basic  Max Min 
1/4 0.2500 1/2 .500 .488 .577 .556 15/64 0.250 0.218
5/16 0.3125 9/16 .562 .546 .650 .622 19/64 0.314 0.280
3/8 0.3750 11/16 .688 .669 .794 .763 23/64 0.377 0.341
7/16 0.4375 3/4 .750 .728 .866 .830 27/64 0.441 0.403
1/2 0.5000 7/8 .875 .850 1.010 .969 31/64 0.504 0.464
9/16 0.5625 15/16 .938 .909 1.083 1.037 35/64 0.568 0.526
5/8 0.6250 1-1/16 1.062 1.031 1.227 1.175 39/64 0.631 0.587
3/4 0.7500 1-1/4 1.250 1.212 1.443 1.382 47/64 0.758 0.710
7/8 0.8750 1-7/16 1.438 1.394 1.660 1.589 55/64 0.885 0.833
1 1.0000 1-5/8 1.625 1.575 1.876 1.796 63/64 1.012 0.956
1-1/8 1.1250 1-13/16 1.812 1.756 2.093 2.002 1-7/64 1.139 1.079
1-1/4 1.2500 2 2.000 1.938 2.309 2.209 1-7/32 1.251 1.187
1-3/8 1.3750 2-3/16 2.188 2.119 2.526 2.416 1-11/32 1.378 1.310
1-1/2 1.5000 2-3/8 2.375 2.300 2.742 2.622 1-15/32 1.505 1.433
1-5/8 1.6250 2-9/16 2.562 2.481 2.959 2.828 1-19/32 1.632 1.556
1-3/4 1.7500 2-3/4 2.750 2.662 3.175 3.035 1-23/32 1.759 1.679
2 2.000  3-1/8 3.125 3.025 3.608 3.449 1-31/32 2.013 1.925
2-1/4 2.2500 3-1/2 3.500 3.388 4.041 3.862 2-13/64 2.251 2.155
2-1/2 2.5000 3-7/8 3.875 3.750 4.474 4.275 2-29/64 2.505 2.401
2-3/4 2.7500 4-1/4 4.250 4.112 4.907 4.688 2-45/64 2.759 2.647
3 3.000 4-5/8 4.625 4.475 5.340 5.102 2-61/64 3.013 2.893
3-1/4 3.2500 5 5.000 4.838 5.774 5.515 3-3/16 3.252 3.124
3-1/2 3.5000 5-3/8 5.375 5.200 6.207 5.928 3-7/16 3.506 3.370
3-3/4 3.7500 5-3/4 5.750 5.562 6.640 6.341 3-11/16 3.760 3.616
4 4.0000 6-1/8 6.125 5.925 7.073 6.755 3-15/16 4.014 3.862

Weight Chart Of Heavy Hex Nuts

Size
Finished Hex
Heavy Hex
Finished Jam
Heavy Hex Jam
Square
Heavy Square
1/2"
3.750
6.540
2.620
4.000
5.780
7.870
5/8"
7.330
11.900
4.930
6.960
10.800
14.300
3/4"
11.900
19.300
7.700
11.000
15.400
23.500
7/8"
19.000
29.700
12.000
16.700
24.500
36.200
1"
28.300
42.500
17.600
23.500
36.300
51.500
1-1/8"
40.300
59.200
24.700
32.400
52.500
72.400
1-1/4"
54.300
78.600
36.100
45.800
70.600
95.500
1-3/8"
73.000
102.000
47.900
59.300
94.500
125.000
1-1/2"
94.300
131.000
60.900
74.800
122.000
161.000
1-5/8"
162.000
91.600
1-3/4"
151.000
204.000
100.000
114.000
1-7/8"
241.000
134.000
2"
224.000
299.000
140.000
165.000
2-1/4"
419.000
227.000
2-1/2"
564.000
332.000
2-3/4"
738.000
429.000
3"
950.000
545.000
3-1/4"
1194.000
651.000
3-1/2"
1526.000
851.000
3-3/4"
1812.000
1005.000
4"
2180.000
1200.000

Stainless Steel Heavy Hex Nuts - Grades

  • Stainless Steel 304 Heavy Hex Nuts
  • Stainless Steel 304L Heavy Hex Nuts
  • Stainless Steel 304H Heavy Hex Nuts
  • Stainless Steel 310 Heavy Hex Nuts
  • Stainless Steel 310S Heavy Hex Nuts
  • Stainless Steel 310H Heavy Hex Nuts
  • Stainless Steel 316 Heavy Hex Nuts
  • Stainless Steel 316L Heavy Hex Nuts
  • Stainless Steel 316Ti Heavy Hex Nuts
  • Stainless Steel 317 Heavy Hex Nuts
  • Stainless Steel 317L Heavy Hex Nuts
  • Stainless Steel 321 Heavy Hex Nuts
  • Stainless Steel 321H Heavy Hex Nuts
  • Stainless Steel 347 Heavy Hex Nuts
  • Stainless Steel 347H Heavy Hex Nuts
  • Stainless Steel 904L Heavy Hex Nuts
  • Stainless Steel 410 Heavy Hex Nuts
  • Stainless Steel 446 Heavy Hex Nuts
  • SMO 254 Heavy Hex Nuts
  • 17-4 PH Stainless Steel Heavy Hex Nuts

Grades of Nickel Alloys Heavy Hex Nuts

  • Inconel 600 Heavy Hex Nuts
  • Inconel 601 Heavy Hex Nuts
  • Inconel 625 Heavy Hex Nuts
  • Inconel 718 Heavy Hex Nuts
  • Incoloy 800 Heavy Hex Nuts
  • Incoloy 825 Heavy Hex Nuts
  • Monel 400 Heavy Hex Nuts
  • Monel K500 Heavy Hex Nuts
  • Nickel 200 Heavy Hex Nuts
  • Nickel 201 Heavy Hex Nuts
  • Hastelloy C276 Heavy Hex Nuts
  • Hastelloy C22 Heavy Hex Nuts
  • Hastelloy B2 Heavy Hex Nuts
  • Hastelloy B3 Heavy Hex Nuts
  • Hastelloy X Heavy Hex Nuts

Duplex Steel Heavy Hex Nuts- Grades

  • UNS S32205 Heavy Hex Nuts
  • UNS S31803 Heavy Hex Nuts

Super Duplex Steel Heavy Hex Nuts - Grades

  • UNS S32750 Heavy Hex Nuts
  • UNS S32760 Heavy Hex Nuts

Inconel/Incoloy Heavy Hex Nuts - Grades

  • Inconel 600 Heavy Hex Nuts
  • Inconel 601 Heavy Hex Nuts
  • Inconel 625 Heavy Hex Nuts
  • Inconel 718 Heavy Hex Nuts
  • Incoloy 800 Heavy Hex Nuts
  • Incoloy 825 Heavy Hex Nuts

Monel Heavy Hex Nuts - Grades

  • Monel 400 Heavy Hex Nuts
  • Monel K500 Heavy Hex Nuts

Nickel Heavy Hex Nuts - Grades

  • Nickel 200 Heavy Hex Nuts
  • Nickel 201 Heavy Hex Nuts

Hastelloy Heavy Hex Nuts - Grades

  • Hastelloy C276 Heavy Hex Nuts
  • Hastelloy C22 Heavy Hex Nuts
  • Hastelloy B2 Heavy Hex Nuts
  • Hastelloy B3 Heavy Hex Nuts
  • Hastelloy X Heavy Hex Nuts

Titanium Heavy Hex Nuts - Grades

  • Titanium Grade 2 Heavy Hex Nuts
  • Titanium Grade 5 Heavy Hex Nuts

Tantalum Heavy Hex Nuts- Grades

  • UNS R05200 Heavy Hex Nuts
  • UNS R05252 Heavy Hex Nuts
  • UNS R05255 Heavy Hex Nuts
  • UNS R05400 Heavy Hex Nuts

Cupro Nickel Heavy Hex Nuts - Grades

  • CuNi 90/10 Heavy Hex Nuts
  • CuNi 70/30 Heavy Hex Nuts

Copper Heavy Hex Nuts - Grades

  • UNS C11000 Heavy Hex Nuts
  • UNS C10100 Heavy Hex Nuts
  • UNS C10200 Heavy Hex Nuts
  • UNS C12000 Heavy Hex Nuts
  • UNS C12200 Heavy Hex Nuts

Carbon Steel Heavy Hex Nuts - Grades

  • Carbon Steel AISI 1018 Heavy Hex Nuts
  • Carbon Steel AISI 1020 Heavy Hex Nuts
  • Carbon Steel AISI 1040 Heavy Hex Nuts
  • Carbon Steel AISI 1045 Heavy Hex Nuts

Alloy Steel Heavy Hex Nuts - Grades

  • Alloy Steel 4130 Heavy Hex Nuts
  • Alloy Steel 4140 Heavy Hex Nuts
  • Alloy Steel 4340 Heavy Hex Nuts
  • Alloy Steel 8620 Heavy Hex Nuts
  • ASTM A193 Alloy Steel Gr B7 Heavy Hex Nuts
  • ASTM A193 Alloy Steel Gr B7M Heavy Hex Nuts
  • ASTM A320 Alloy Steel Gr L7 Heavy Hex Nuts
  • ASTM A320 Alloy Steel Gr L7M Heavy Hex Nuts
  • ASTM A320 Alloy Steel Gr L43 Heavy Hex Nuts
  • ASTM A320 Alloy Steel Gr L43 Heavy Hex Nuts
  • ISO 898-1 Alloy Steel Gr 8.8 Heavy Hex Nuts
  • ISO 898-1 Alloy Steel Gr 10.9 Heavy Hex Nuts
  • ISO 898-1 Alloy Steel Gr 12.9 Heavy Hex Nuts

Brass Heavy Hex Nuts - Grades

  • UNS C21000 Heavy Hex Nuts
  • UNS C22000 Heavy Hex Nuts
  • UNS C22600 Heavy Hex Nuts
  • UNS C23000 Heavy Hex Nuts
  • UNS C24000 Heavy Hex Nuts
  • UNS C26000 Heavy Hex Nuts
  • UNS C26800 Heavy Hex Nuts
  • UNS C27000 Heavy Hex Nuts
  • UNS C27200 Heavy Hex Nuts
  • UNS C28000 Heavy Hex Nuts
  • UNS C33000 Heavy Hex Nuts
  • UNS C33500 Heavy Hex Nuts
  • UNS C34000 Heavy Hex Nuts
  • UNS C34200 Heavy Hex Nuts
  • UNS C35300 Heavy Hex Nuts
  • UNS C35600 Heavy Hex Nuts

Aluminium Heavy Hex Nuts - Grades

  • Aluminium Alloy 1050 Heavy Hex Nuts
  • Aluminium Alloy 1060 Heavy Hex Nuts
  • Aluminium Alloy 1060 Heavy Hex Nuts
  • Aluminium Alloy 1070 Heavy Hex Nuts
  • Aluminium Alloy 1080 Heavy Hex Nuts
  • Aluminium Alloy 1100 Heavy Hex Nuts
  • Aluminium Alloy 1145 Heavy Hex Nuts
  • Aluminium Alloy 2011 Heavy Hex Nuts
  • Aluminium Alloy 2014 Heavy Hex Nuts
  • Aluminium Alloy 2017 Heavy Hex Nuts
  • Aluminium Alloy 2024 Heavy Hex Nuts
  • Aluminium Alloy 2090 Heavy Hex Nuts
  • Aluminium Alloy 3003 Heavy Hex Nuts
  • Aluminium Alloy 5052 Heavy Hex Nuts
  • Aluminium Alloy 5083 Heavy Hex Nuts
  • Aluminium Alloy 6061 Heavy Hex Nuts
  • Aluminium Alloy 6063 Heavy Hex Nuts
  • Aluminium Alloy 6066 Heavy Hex Nuts
  • Aluminium Alloy 6082 Heavy Hex Nuts
  • Aluminium Alloy 7050 Heavy Hex Nuts
  • Aluminium Alloy 7075 Heavy Hex Nuts

Zirconium Heavy Hex Nuts - Grades

  • UNS R60700 Heavy Hex Nuts
  • UNS R60702 Heavy Hex Nuts
  • UNS R60704 Heavy Hex Nuts
  • UNS R60705 Heavy Hex Nuts
  • UNS R60706 Heavy Hex Nuts

Beryllium Copper Heavy Hex Nuts - Grades

  • UNS C17200 Heavy Hex Nuts
  • UNS C17300 Heavy Hex Nuts
  • UNS C17500 Heavy Hex Nuts
  • UNS C17510 Heavy Hex Nuts

Phosphor Bronze Heavy Hex Nuts - Grades

  • UNS C51000 Heavy Hex Nuts
  • UNS C51900 Heavy Hex Nuts
  • UNS C52100 Heavy Hex Nuts
  • UNS C54400 Heavy Hex Nuts

Silicon Bronze Heavy Hex Nuts - Grades

  • UNS C65100 Heavy Hex Nuts
  • UNS C65500 Heavy Hex Nuts
  • UNS C66100 Heavy Hex Nuts

Key Technical Features

  • Enhanced Load Distribution Geometry: Larger thickness and width compared to standard nuts ensures better load spreading across bolted joints, reducing localized stress concentrations in structural assemblies.
  • High Torque Resistance Design: Engineered to withstand high tightening torque values without thread stripping, making them suitable for preloaded bolted connections in steel structures.
  • Dimensional Precision Compliance: Manufactured with strict adherence to DIN and ASTM dimensional tolerances, ensuring interchangeability in global bolting systems and automated assembly lines.
  • Corrosion Resistance Options: Stainless steel and galvanized variants provide strong resistance against atmospheric corrosion, marine exposure, and chemical environments.
  • Vibration Resistance Stability: When paired with high-tensile bolts, heavy hex nuts maintain clamping force under cyclic loading and vibration-heavy conditions.
  • Material Strength Optimization: Available in quenched and tempered alloy steel grades for high tensile applications exceeding 1000 MPa load-bearing requirements.
  • Thread Accuracy & Engagement: Precision-machined threads ensure full engagement with bolts, minimizing loosening risk under dynamic loads.
  • Surface Treatment Versatility: Multiple coating options improve service life in offshore, petrochemical, and high-humidity environments.

Industry Applications

Heavy hex nuts are widely used in high-load and safety-critical fastening systems where standard nuts are insufficient. They are preferred in applications requiring structural integrity, vibration resistance, and compliance with engineering codes.

  • Steel Structure Construction: Used in bolted joints of beams, columns, and trusses in bridges and high-rise buildings.
  • Oil & Gas Refineries: Securing pipeline flanges, pressure vessels, and refinery structural frames exposed to high pressure and temperature.
  • Power Generation Plants: Applied in turbine assemblies, boiler structures, and heavy equipment foundations.
  • Railway Infrastructure: Used in track fastening systems and heavy-duty rail support structures.
  • Wind Energy Systems: Securing tower sections and nacelle assemblies in wind turbine installations.
  • Mining Equipment: Ensures joint integrity in crushers, conveyors, and heavy excavation machinery.
  • Marine Engineering: Used in shipbuilding structures and offshore platforms exposed to saltwater corrosion.

Manufacturing & Quality Assurance

Heavy hex nuts are manufactured using cold forging and hot forging techniques depending on material grade and size. The process begins with precision wire cutting followed by forging under controlled pressure to achieve the required geometric structure. Threads are then rolled or cut using CNC machining systems to ensure dimensional accuracy and mechanical consistency.

Each batch undergoes strict quality control including hardness testing, dimensional inspection using calibrated gauges, and surface finish verification. Lot traceability is maintained for every production batch to ensure compliance with international standards.

At KK Fasteners, quality assurance protocols align with ISO 9001 systems, with additional compliance checks for RoHS and REACH requirements for global export markets.

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Heavy Hex Nuts - FAQs

Heavy hex nuts are high-strength fasteners with larger width and thickness than standard hex nuts, designed for structural and industrial applications. They provide better load distribution and higher torque resistance, making them suitable for use in high-stress bolted connections such as steel structures and heavy machinery.

Heavy hex nuts are typically manufactured from carbon steel, alloy steel, and stainless steel grades such as SS 304 and SS 316. Carbon steel offers high strength, stainless steel provides corrosion resistance, and alloy steel is used for demanding applications involving high pressure and temperature.

Heavy hex nuts are produced according to international standards such as ASTM A563, ASTM A194, DIN 934, ISO 4032, and BS specifications. These standards define mechanical properties, dimensions, and performance requirements to ensure compatibility with global fastening systems.

Heavy hex nuts are widely used in structural steel fabrication, oil and gas installations, power plants, wind energy systems, and heavy equipment assembly. Their design makes them ideal for applications requiring strong, vibration-resistant fastening under high loads.

A reliable supplier should offer certified quality systems, compliance with ASTM and DIN standards, and full material traceability. It is also important to evaluate manufacturing capability, testing procedures, and export experience. Suppliers like KK Fasteners support global buyers with consistent quality and technical documentation.

Heavy Hex Nuts - Export Destination

Heavy Hex Nuts Supplier in North America
Antigua and Barbuda, Bahamas, Barbados, Belize, Canada, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago, United States.
Heavy Hex Nuts Supplier in South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela.
Heavy Hex Nuts Supplier in Europe
Albania, Andorra, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic (Czechia), Denmark, Estonia, Finland, France, Germany, Greece, Holy See, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Monaco, Montenegro, Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Russia, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom.
Heavy Hex Nuts Supplier in Asia
Afghanistan, Armenia, Azerbaijan, Bahrain, Bangladesh, Bhutan, Brunei, Cambodia, Cyprus, Georgia, India, Indonesia, Iran, Iraq, Israel, Japan, Jordan, Kazakhstan, Kuwait, Kyrgyzstan, Laos, Lebanon, Malaysia, Maldives, Mongolia, Myanmar, Nepal, Oman, Pakistan, Palestine, Philippines, Qatar, Saudi Arabia, Singapore, South Korea, Sri Lanka, State of Palestine, Syria, Taiwan, Tajikistan, Thailand, Timor-Leste, Turkey, Turkmenistan, United Arab Emirates, Uzbekistan, Vietnam, Yemen.
Heavy Hex Nuts Supplier in Australia
Australia, Fiji, Kiribati, Marshall Islands, Micronesia, Nauru, New Zealand, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, Vanuatu.

Heavy hex nuts play a critical role in ensuring structural safety across demanding industrial environments. Their performance depends on precise manufacturing, material selection, and compliance with global fastening standards.

For engineered fastening solutions with full traceability and export-ready quality control, KK Fasteners supports OEMs, EPC contractors, and distributors with reliable supply and technical support.

Request a detailed quotation or connect with the engineering team to get application-specific specifications and pricing support.

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