Cap Nuts

Custom Nuts Manufacturer


Cap Nuts


Heatfastener is a professional engaged in the production of Cap nuts and custom screws and 23 years of research and development of screw suppliers that supply made-to-order screws per your print.  Products are widely used in automotive, construction, mining, communications, electronics, and other fields. Our company is equipped with advanced production equipment and testing instruments, such as Taiwan’s multi-station cold heading machine, thread rolling machines, precision stampings for production of hydraulic, as well as precision machining parts Taiwan used automatic lathe, CNC lathe and so on. At the same time, we have several engineers with more than 30 years of experience in machinery manufacturing and development and own specialized testing staff effectively to ensure the quality of the manufactured products. The company always strictly follows the quality management system ISO9001 standards. At present, our products are exported to Europe and the United States, the Middle East, Southeast Asia, Africa, and many other countries and regions. Many professional partners are enjoying our services. We welcome OEM orders and expect to strengthen our business cooperation with customers from all over the world and create a bright future together.

With ISO9001:2008,iso14001:2004, and especially IAFT16949:2009 certification for the automotive industry. Heatfastener offers fully customized custom bolts and screws, custom nuts according to your needs. We can bring your fastener design to reality, and everything according to your requirements.

Cap nuts

Cap Nuts Details

Acorn nuts, also known as Crown Hex Nuts, Blind Nuts, Cap Nuts, or Domed Cap Nuts, are utilized for both safety and appearance. Their crown caps protect and prevent stripping of screws and bolts so they can easily be removed and reused. Acorn nuts also add a finished look to any project and are commonly made with stainless steel or plated with brass or zinc. Low crown (standard) steel cap nuts are usually manufactured in two pieces, a hex nut, and an acorn-shaped top, with a zinc die-cast to form the finished nut. Stainless steel cap nuts are similar in design to the steel nut but made from an austenitic stainless alloy, and can be a one or two-piece style. Additional styles of acorn nuts include high crown and self-locking

Heatfastener carries a wide range of cap nuts in various grades, materials, and styles. We carry both inches and metrics. If you are looking for an uncommon size, length, or material, it is something we can make for you. We can make your hex nut per your print, We can also manufacture these items in special materials and custom made as below listed:


  • Stainless steel – SS302, SS304, SS316, (good tenacity),Stainless steel A2 A4
  • Steel – C45(K1045), C46(K1046),C20
  • Brass – C36000 ( C26800), C37700 ( HPb59), C38500( HPb58),C27200CuZn37), C28000(CuZn40)
  • Bronze–C51000, C52100, C54400, etc
  • Aluminum – Al6061, Al6063 etc
  • Carbon steel – C1006,C1010,C1018,C1022,C1035K,C1045
  • Alloy steel – SCM435,C10B21,C10B339
  • Other material– Titanium, UNS C11000 Copper,silicon


  • Grade: Grade 4.8,Grade 6.8,Grade 8.8,Grade10.9,Grade12.9 etc
  • Standard:GB,DIN,ISO, ANSI/ASTM,BS,BSW,JIS, Metric, Inch
  • Finish:Plain, H.D.G, Black oxide, Chrome, Teflon,dacromet,Anodized,With nylok
  • Certificates: ISO9001:2015, ISO14001:2015,IATF16949, ROHS
  • Custom Made:OEM is available,according to customer requirments

Head type&Drive Type

  • Head Type:Flat, Oval, Binding, Pan, Round, Truss, Button, PF,Cheese,Fillister, Pan Washer, Cylinder,Hexagon, Indented Hexagon,Washer
  • Drive Type:Phillips, Slotted, Phiilips/Slotted, 6 Lobe, Pin 6 Lobe, Pozidrive, Square, Triangle,Y type. Tri-wing, S-type, H type, Hexagon, 5 Point,8 point, Spline, Spanner, Clutch, Hex pn,torx pin
  • Machine Screw, Tapping screws,threading cutting screw,threading forming screw


Use an acorn nut to protect and give a finished look to an exposed bolt end. Cap nuts prevent stripping of screws and bolts on engines, machinery, and wood frames so they can be easily removed and reused. Brass nuts are commonly chosen for plumbing and electrical applications. Use acorn nuts from Grainger to protect exposed ends of threaded fasteners indoors and out.

Also, our custom fastener, bolts, screws are widely used in the below industries

  • Electronics
  • Petrochemicals
  • Consumer products
  • Transportation
  • Agriculture
  • Heavy machinery
  • Construction
  • Automotive
  • Medical
  • Military
  • Aerospace
  • Oil and gas

An cap nut, also referred to as crown hex nut, blind nut, acorn nut, domed cap nut, or dome nut(UK), is a nut that has a domed end on one side, when used together with a threaded fastener with an external male thread, the domed end encloses the external thread, either to protect the thread or to protect the nearby objects from contact with the thread, in addition, the dome gives a more finished appearance

Acorn nuts are usually made of brass, steel, stainless steel, or nylon, they can be chrome plated and given a mirror finish

There are two types of acorn nuts, one is low, or the standard acorn nut, the other is the high acorn nut, the high acorn nut is wider and higher and will protect extra long studs, there are also self locking acorn nuts that have distorted threads in the hex area to create a tight friction fit to prevent the nut from vibrating loose

We supply all kinds of cap nuts or specialty cap nuts. from small to large.ISO4034 Hexagon Nuts Dimensions sizes chart

Thread size(d)M4M5M6M8M10M12M14M16M20
PitchCoarse thread0.70.811.251.51.75222.5
Fine Thread 1///
Fine thread 2////1.251.25//1.5
h1Nominal size5.667.58.910.513.515.516.521
h2Nominal Size9.610.5121418.122.526.427.535
rmax=nominal size2.533.
max=nominal size78101316 | 1718 | 1921 | 222430
min6.787.789.7812.7315.73 | 16.7317.73 | 18.6720.67 | 21.6723.6729.16
per 1000 units kg1.41.553.35.310.1 | 10.718.3 | 19.026.1 | 26.837.1111

Need Custom Nuts for Your Industry?

As a 20-year industry experience manufacturer with a factory equipped with precision machines, we can provide, from consultation to production, a one-stop solution for you.

About Us

Shenzhen Heat Hardware Co., Ltd is a leading custom screw manufacturer in China founded in 2000 years. We are specializing in custom screws, security screws, Sems screws, Chicago Screws, Weld Screws, Long screws, Micro Screws, Thumb Screws, Set Screws, Custom bolts, carriage bolts, nuts, and other custom Fasteners. With more than 20years of industry experience. We have serviced over 20000customers including the aerospace industry, automotive industry, electronics, mechanical and electrical products, robots, the Medical industry, communications industry, Outdoor sports products, smart appliances, etc. we can provide one-stop fastener customized service for you no matter what kind of custom fastener you need.

Frequently Asked Questions

Place the end of a measuring tape on one of the flat sides of the nut’s outer perimeter. Stretch the tape measure across the nut’s diameter to the flat-side directly across from the one you pulling from. If the nut is metric, count the number of lines on the tape measure to find the measurement.

A cap nut serves to protect the bolt threads underneath, but also provides a cleaner appearance, and may improve safety on certain joints and applications. When your application requires a smooth finish or all rough-edged fasteners and exposed threads must be covered, cap nuts provide an excellent solution.

These axle caps really aren’t designed to be reused, but they can be if they’re removed carefully. i.e., when you get them off, you might find you have to run to the store to get replacements anyway

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