Cap nuts are indispensable fasteners for structural connections in industrial machinery production.

Cap nuts are indispensable fasteners for structural connections in industrial machinery production.

Cap nut is a standard fastener; its primary role is to fix and connect a variety of metal parts, such as bolts, screws, etc., to ensure that it will not loosen or fall off in the process of use. Cap nut, as the name implies, is a hexagonal nut with a cover; the role of this cover is to fasten the outer exposed part of the cover to prevent moisture or some other corrosive substances from the inside to play a role in preventing rust, which in turn improves its own as well as the use of connecting parts of the time.

Cap nuts are widely used in machinery, equipment, construction, and other fields. This article will introduce the basic concept, classification, characteristics, applications, and future development trends of cap nuts.

What are the materials of cap nuts?

A cap nut is a hexagonal or square-shaped nut, usually made of carbon steel, stainless steel, copper, aluminum alloy, and other materials. Its shape is similar to that of an ordinary nut, but it has a raised part at the top, which can be fitted with various shapes of metal parts to realize the purpose of fixing and connecting.

1. A cap nut is a hexagonal or square nut, usually made of carbon steel, stainless steel, copper, aluminum alloy, and other materials. Its shape is similar to that of an ordinary nut, but it has a raised part at the top, which can be matched with metal parts of various shapes to realize the purpose of fixing and connecting.

2. The American Standard ASME B18.2.1 and the International Standard ISO 8802-1:2008 usually specify the dimensions of cap nuts and provide detailed regulations on their dimensions, tolerances, materials, surface treatment, and other aspects.

Classification of Cap Nuts

Cap nuts can be categorized into various types according to their shape, of which the common ones are hexagonal and square. According to their use, cap nuts can be classified into standard cap nuts, anti-loosening cap nuts, etc. Ordinary cap nuts are suitable for general fixing and connection; anti-loosening cap nuts have an anti-loosening function, applicable to the need to prevent the bolt from loosening on occasion; and cap nuts have higher mechanical strength, relevant to the need to withstand more excellent load occasions.

Cap nuts are graded according to their material and endurance level and other characteristics, and the common cap nut grades are as follows:

1.4 level cap nuts: suitable for low-strength applications, the maximum loosening torque does not exceed 20N/m.

2.8 level cap nuts: The maximum loosening moment applies to medium-strength applications and does not exceed 60N/m.

Grade 10 cap nuts: suitable for high-strength applications, the maximum loosening moment does not exceed 90N/m.

The above levels of cap nuts, their characteristics, and their uses are also different.

18-8 Stainless Steel Cap Nuts;

Super-Corrosion-Resistant 316 Stainless Steel Cap Nuts；

Metric Super-Corrosion-Resistant 316 Stainless Steel Cap Nuts；

Metric Low-Strength Steel Cap Nuts；

High-Strength Steel Cap Nuts—Grade 8；

Metric High-Strength Steel Cap Nuts—Class 10；

Plastic Cap Nuts；

Brass Cap Nuts；

Aluminum Cap Nuts；

Low-Profile Cap Nuts；

Metric Nylon-Insert Cap Locknuts： A nylon insert on these metric nuts prevents vibration from loosening them, and a domed head protects the threads at the end of the bolt from damage and debris. These nuts are reusable, but the nylon insert holds insert creases for each use. Also known as acorn nuts, they create a finished appearance and can reduce snagging on wires and insulation. Nuts meet DIN 986, an international standard for domed cap nut dimensions.

These nuts are made of robust, wear-resistant Class 6 steel. Zinc plating extends the nuts' life by protecting the inner steel from rust.

Low-Strength Steel Distorted-Thread Cap Locknuts；

Super-Corrosion-Resistant 316 Stainless Steel Vibration-Resistant Cap Locknuts；

Super-corrosion-resistant 316 Stainless Steel Distorted-Thread Cap Locknuts；

Metric 18-8 Stainless Steel Vibration-Resistant Cap Locknuts。

Features of cap nuts

　1. Simple structure: Cap nuts have a relatively simple structure, mainly composed of hexagonal or square nuts and raised parts, and are easy to manufacture and maintain.

　2. Reliable connection: the cap nut and metal parts are very close together, which can ensure the stability and reliability of the connection part.

　3. Convenient operation: Cap nuts are very convenient to use. You only need to put them on the metal parts that need to be fixed and then tighten them with a wrench or power tool.

　4. Wide range of applications: Cap nuts are suitable for fixing and connecting various metal materials, such as steel, cast iron, copper, and aluminum.

　5. Large load bearing: cap nuts can bear large loads and are suitable for fixing and connecting all kinds of heavy machinery and equipment.

Application of Cap Nuts

Cap nuts are widely used in machinery, equipment, construction, and other fields. For example, in automobile manufacturing, cap nuts are used to fix essential parts such as automobile engines, chassis, frames, etc.; in machinery and equipment, cap nuts are used to repair all kinds of transmission parts such as gears, bearings, etc.; in the field of construction, cap nuts are used to restore the reinforcing steel bars in reinforced concrete structures to ensure the stability of the structure.

What are the uses of cap nuts?

Cap nuts are used in the same way as hexagonal nuts. They are characterized by the fact that the central nut is not easy to slide and can only be used with a live wrench, a dull wrench, a dual-purpose wrench (open part), or a special square-hole socket wrench. They are mainly used for rough, simple parts.

Cap nuts can be used where it is necessary to cover the threads on the end of the bolt. They can also be used as tools. Cap nuts and ring nuts can usually be removed by hand rather than with tools and are typically used where frequent removal and small forces are required.

Cap nuts are mainly used for tires and front and rear axles of automobiles, tricycles, electric vehicles, etc. They are also used to secure the bases of road light stands and some mechanical equipment often exposed to sun and rain.

Cap nuts are used in conjunction with hexagonal nuts to play the role of locking hexagonal nuts with better effect. One side of the weld nut welds a thin steel plate with holes, which is then connected to the bolt.

Cap nuts are suitable for high-strength fasteners, mechanical fasteners, furniture fasteners, vehicle fasteners, vehicle processing profiled fasteners, cold head profiled fasteners, double-ended ground foot U-shaped wire, architectural decorative fasteners, and other types of fasteners can also be used in foundation engineering, automobile and motorcycle parts, light industry, machinery, furniture, hardware tools, architectural decoration and so on.

To be more rust-proof, cover nut surfaces generally need to be treated, including galvanized, nickel-plated, chrome-plated, Dacromet, and other surface treatment processes. It improves the service life of fasteners; in these surface treatment processes, chrome-plated is the best process. Chrome-plated products have smooth and bright surfaces, and rust and corrosion are longer, comparable to stainless steel.

(1)Cap nut and stainless steel hexagon slotted nut with cotter pin and screw with hole bolt, used to withstand vibration, alternating load occasions, can prevent the nut from loosening out.

(2) Cap nut with inserts. Inserts rely on tightening the nut, tapping out the internal threads, preventing loosening, and having good elasticity.

(3) Cap and hexagonal nuts use the same, characterized by mounting and dismantling the central nut with a wrench card. It is not easy to slip but can only be used with a live wrench, dull wrenches, dual-purpose wrenches (open part), or special square hole socket wrenches for mounting and dismantling and mainly used for rough, simple components.

(4) A cap nut can be used in the bolt end threads needed to cover the recruitment occasion.

(5) Cap nuts can be used on workpieces.

(6) Cap nuts and ring nuts can be disassembled by hand without tools. They are usually used when frequent disassembly is required, and the force is insignificant.

(7) Cap nuts are mainly used in automobiles, tricycles, electric cars, and other tires. The front and rear axles play a role in fixing the tires, and the front and rear can also be used to restore the base of street lamps that are often exposed to sunlight and rain, as well as some mechanical equipment.

Development trend of cap nuts

　1. Changes in cap nuts: With the increasing requirements for structural strength and stability in machinery, equipment, and construction, the demand for cap nuts is also increasing. Therefore, one of the future development directions of cap nuts is to improve their mechanical strength and stability.

　2. Miniaturization: Miniaturized cap nuts are needed in electronic products, medical equipment, optical instruments, and other fields. Therefore, one of the development directions of future cap nuts is to realize miniaturization.

　3. Environmental protection: As people's attention to environmental protection continues to increase, the demand for environmentally friendly cap nuts is also growing. Therefore, the future development direction of cap nuts is environmental protection. Environmentally friendly cap nuts are usually made of stainless steel, aluminum alloy, and other recyclable materials to reduce environmental pollution and achieve resource recycling.

In short, as a standard fastener, cap nuts will still be widely used.

If you need help with zinc-nickel alloy for surface finishes, cap nuts, or structural connections, contact our customer service team at adelajonly@gmail.com or www.juxinfasteners.com.