Hex Cap Nuts

Manufacturer, Exporter & Supplier of Hex Cap Nut

Industrial Hex Cap Nuts – Precision Fastening Solutions in Stainless & Alloy Grades

Hex Cap Nuts are precision-engineered threaded fasteners designed to secure bolts and threaded rods in structural, mechanical, and industrial assemblies. Manufactured in hexagonal form for easy torque application, these nuts comply with international standards such as DIN 1587, ISO 4032, and ASTM A194, ensuring compatibility across global engineering systems. They are widely used in industries such as construction, oil & gas, heavy machinery, and automotive manufacturing, where secure fastening and load distribution are critical.

Available in materials like stainless steel (SS 304, SS 316), carbon steel, and alloy steel, Hex Cap Nuts offer varying levels of strength, corrosion resistance, and temperature performance. Their closed-end cap design provides added protection to exposed threads, preventing damage and enhancing safety in exposed environments.

KK Fasteners supplies these components to global markets with full material traceability, supporting OEMs and EPC contractors who require consistent quality and compliance across projects.

Technical Hex Cap Nuts Specifications​

Parameter Specification
Material Variants Stainless Steel (SS 304, 316, 316L), Carbon Steel, Alloy Steel
Grades A2-70, A4-80, Grade 2, Grade 5, Grade 8
Size Range M3 to M64 / 1/8" to 2"
Thread Type Metric, UNC, UNF, BSW
Standards DIN 1587, DIN 917, ISO 4032, ASTM A194, BS 1083
Surface Finish Plain, Zinc Plated, Hot-Dip Galvanized, Black Oxide, PTFE Coated
Type Variants Closed-End Cap Nuts, Dome Nuts, Heavy Hex Cap Nuts
Mechanical Properties Tensile Strength: Up to 800 MPa (depending on grade)

DIN 1587 Hex Cap Nuts Dimension Chart

DIN 1587 Hex Cap Nuts Supplier
threadSeries 1M4M5M6M8M10M12(M14)M16(M18)M20(M22)M24
 Series 2---M8x1M10x1M12x1,5(M14x1,5)(M16x1,5)(M18x1,5)M20x2(M22x1,5)M24x2
 Series 3----M10x1,25M12x1,25--(M18x2)M20x1,5(M22x2)-
PSeries 10,70,811,251,51,75222,52,52,53
damin.45681012141618202224
max.4,65,756,758,7510,81315,117,319,521,623,725,9
dkmax.6,57,59,512,51517202326283334
dwmin.5,96,98,911,614,616,619,622,524,927,731,433,3
e min.Product grade A7,668,7911,0514,3817,7720,0323,3526,7530,1433,5337,7239,98
Product grade B7,58,6310,8914,217,5919,8522,7826,1729,5632,9537,2939,55
x max.Series 11,41,622,53-------
Series 2---22-------
Series 3----2,5-------
g2 max.Series 1-----6,47,37,39,39,39,310,7
Series 2-----5,65,65,65,67,35,67,3
Series 3-----4,9--7,35,67,3-
hmax. nominal size81012151822252832343942
min. P. grade A7,649,6411,5714,5717,5721,4824,4827,4832,3833,3838,3841,38
min. P. grade B7,429,4211,314,317,321,1624,1627,1631333841
mmax.3,2456,58810111315161819
min.2,93,74,76,147,649,6410,312,314,314,916,917,7
Mwmin.2,322,963,764,916,117,718,249,8411,4411,9213,5214,16
rapprox.3,253,754,756,257,58,51011,5131416,517
sMax. = nominal size7810131618212427303436
min. P. grade A6,787,789,7812,7315,7317,7320,6723,6726,6729,6733,3835,38
min. P. grade B6,647,649,6412,5715,5717,5720,1623,1626,1629,163335
tmin.5,267,217,7110,6512,6515,6517,6520,5824,5825,5828,5830,5
max.5,747,798,2911,3513,3516,3518,3521,4225,4226,4229,4231,5
wmin.222223445556
Weight kg/1000pcs --4,661120,128,3-54,395104 
  • s – size of the hexagon
  • t – length of the thread
  • d – the nominal diameter of the thread
  • h – height of the nut
  • m – hight of the nut part
  • dk – head diameter
  • da – Turning diameter shrinkage
  • dw – contact surface diameter
  • mw – minimum wrenching height

Stainless Steel Hex Cap Nuts - Grades

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

Grades of Nickel Alloys Hex Cap Nuts

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

Duplex Steel Hex Cap Nuts- Grades

  • UNS S32205 Hex Cap Nuts
  • UNS S31803 Hex Cap Nuts

Super Duplex Steel Hex Cap Nuts - Grades

  • UNS S32750 Hex Cap Nuts
  • UNS S32760 Hex Cap Nuts

Inconel/Incoloy Hex Cap Nuts - Grades

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

Monel Hex Cap Nuts - Grades

  • Monel 400 Hex Cap Nuts
  • Monel K500 Hex Cap Nuts

Nickel Hex Cap Nuts - Grades

  • Nickel 200 Hex Cap Nuts
  • Nickel 201 Hex Cap Nuts

Hastelloy Hex Cap Nuts - Grades

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

Titanium Hex Cap Nuts - Grades

  • Titanium Grade 2 Hex Cap Nuts
  • Titanium Grade 5 Hex Cap Nuts

Tantalum Hex Cap Nuts- Grades

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

Cupro Nickel Hex Cap Nuts - Grades

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

Copper Hex Cap Nuts - Grades

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

Carbon Steel Hex Cap Nuts - Grades

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

Alloy Steel Hex Cap Nuts - Grades

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

Brass Hex Cap Nuts - Grades

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

Aluminium Hex Cap Nuts - Grades

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

Zirconium Hex Cap Nuts - Grades

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

Beryllium Copper Hex Cap Nuts - Grades

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

Phosphor Bronze Hex Cap Nuts - Grades

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

Silicon Bronze Hex Cap Nuts - Grades

  • UNS C65100 Hex Cap Nuts
  • UNS C65500 Hex Cap Nuts
  • UNS C66100 Hex Cap Nuts

Key Technical Features

  • Designed with a closed-end dome structure that protects exposed threads from corrosion and mechanical damage, improving assembly longevity.
  • Manufactured to ISO tolerance classes (6H), ensuring precise thread engagement and minimizing the risk of loosening under vibration.
  • Capable of handling tensile loads up to 800 MPa (Grade 8 variants), making them suitable for high-load structural applications.
  • Corrosion-resistant stainless steel grades (SS 316) provide excellent performance in marine and chemical environments.
  • Hexagonal geometry allows uniform torque distribution during tightening, reducing stress concentration on mating components.
  • Available with multiple coating options such as hot-dip galvanizing for enhanced outdoor durability.
  • Compatible with standard bolts and threaded rods across DIN, ISO, and ASTM systems, ensuring global interchangeability.
  • Smooth dome finish improves safety by eliminating sharp exposed threads in accessible assemblies.

Industry Applications

Hex Cap Nuts are used in applications where thread protection, secure fastening, and aesthetic finishing are required alongside mechanical strength.

  • Automotive Assemblies — Used in wheel hubs and exposed bolt connections to protect threads and improve safety.
  • Construction & Structural Steel — Secures structural joints where exposed bolts require corrosion protection.
  • Oil & Gas Equipment — Applied in pipelines and flange connections to prevent thread damage in harsh environments.
  • Marine Installations — Stainless steel variants resist saltwater corrosion in shipbuilding and offshore platforms.
  • Industrial Machinery — Used in rotating equipment and housings to maintain secure fastening under vibration.
  • Electrical Enclosures — Provides safe, enclosed fastening points without exposed sharp threads.
  • Railway Infrastructure — Used in track systems and mechanical joints requiring durability and tamper resistance.

Manufacturing & Quality Assurance

Hex Cap Nuts are typically produced using cold forging or hot forging processes, followed by precision CNC machining to achieve accurate thread profiles and dimensional consistency. Thread rolling ensures superior surface finish and enhanced fatigue strength compared to cut threads.

Quality control involves dimensional inspection using calibrated gauges, hardness testing (Rockwell scale), and coating thickness verification for plated variants. Each batch undergoes material traceability checks aligned with ISO 9001 quality management systems.

At KK Fasteners, inspection protocols include lot-based documentation, ensuring that every shipment meets international standards and client-specific requirements.

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Send us your Requirement for Hex Cap Nuts

We can assure you one of best prices in the Industry. We respond to all enquiries with in 4-8 hours on all business days. Send us your requirement on inquiry@kkfasteners.com
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Hex Cap Nuts - FAQs

Hex Cap Nuts are closed-end hexagonal fasteners designed to cover and protect exposed bolt threads while providing secure fastening. They are commonly used in structural and mechanical assemblies where safety, corrosion resistance, and a clean finished appearance are required.

Hex Cap Nuts are typically manufactured in stainless steel (SS 304, SS 316), carbon steel, and alloy steel. Stainless steel provides excellent corrosion resistance, while carbon and alloy steels offer higher tensile strength for heavy-duty and structural applications.

Hex Cap Nuts are produced in accordance with international standards such as DIN 1587 (dome nuts), DIN 917 (high cap nuts), ISO 4032, and ASTM A194. These standards ensure dimensional accuracy and compatibility with global fastening systems.

The correct selection depends on load requirements, environmental conditions, and thread compatibility. For corrosive environments, stainless steel 316 is recommended, while high-strength alloy steel grades are suitable for applications involving heavy loads or dynamic stress.

A reliable supplier should offer ISO-certified production, full material traceability, and compliance with international standards. KK Fasteners supports global clients with consistent quality, documented testing, and experience in supplying across multiple industries.

Hex Cap Nuts - Export Destination

Hex Cap 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.
Hex Cap Nuts Supplier in South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela.
Hex Cap 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.
Hex Cap 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.
Hex Cap Nuts Supplier in Australia
Australia, Fiji, Kiribati, Marshall Islands, Micronesia, Nauru, New Zealand, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, Vanuatu.

Precision fastening requires consistency in both design and manufacturing. Hex Cap Nuts supplied by KK Fasteners are engineered to meet global standards while supporting project-specific customization. For detailed specifications, material certifications, or bulk pricing, request a quote or connect with the engineering team to discuss your application requirements.