Secondary Operations On Metal Fasteners: What Are They And Why Are They Important?

A guide to the different types of secondary operations that can enhance the performance and appearance of metal fasteners. 

What Are Secondary Operations?

Metal fasteners are essential components in many industries, such as construction, automotive, aerospace, and medical. They are used to join or secure parts together, and they come in various shapes, sizes, and materials. However, sometimes the standard fasteners are not enough to meet the specific requirements of a project. That's where secondary operations come in.

Secondary operations are additional processes that are performed on fasteners after they are manufactured. They can improve the functionality, durability, or aesthetics of the fasteners, depending on the desired outcome. Some of the most common secondary operations are:

• Drilling: creating holes or slots in the fasteners to allow for easy installation or alignment
• Threading: cutting grooves or ridges on the fasteners to enable them to mate with other threaded parts
• Grinding: smoothing or polishing the surface of the fasteners to remove burrs, sharp edges, or irregularities
• Plating: coating the fasteners with a thin layer of metal or alloy to enhance their corrosion resistance, electrical conductivity, or appearance
• Painting: applying a layer of paint or powder to the fasteners to change their color, texture, or reflectivity

Drilling

Drilling is one of the most basic and versatile secondary operations on metal fasteners. It involves using a drill bit to create holes or slots in the fasteners, either partially or completely. Drilling can serve several purposes, such as:

• Enabling the fasteners to be inserted into pre-drilled holes or slots in the mating parts, ensuring a precise and secure fit
• Allowing the fasteners to be attached to the mating parts with screws, nails, rivets, or pins, increasing their holding strength
• Providing clearance for wires, cables, pipes, or tubes to pass through the fasteners, facilitating electrical or fluid connections

Drilling can be done on various types of metal fasteners, such as bolts, nuts, washers, pins, and clips. However, drilling also poses some challenges, such as:

• Requiring precise alignment and positioning of the drill bit and the fastener, to avoid damaging the fastener or creating inaccurate holes or slots
• Generating heat and friction, which can cause the fastener or the drill bit to wear out or deform
• Creating chips or shavings, which can contaminate the fastener or the work environment, and require proper disposal

To overcome these challenges, it is important to use the appropriate drill bit size, speed, and feed rate, as well as to lubricate and cool the fastener and the drill bit during the drilling process. It is also advisable to use a drill press or a CNC machine to ensure accuracy and consistency.

Threading

Threading is another common and useful secondary operation on metal fasteners. It involves cutting grooves or ridges on the fasteners, either internally or externally, to create threads. Threads enable the fasteners to mate with other threaded parts, such as screws, bolts, nuts, or rods, forming a tight and adjustable connection. Threading can offer several advantages, such as:

• Increasing the load-bearing capacity of the fasteners, as the threads distribute the force evenly along the contact surface
• Enhancing the sealing performance of the fasteners, as the threads create a close fit that prevents leakage of fluids or gases
• Allowing the fasteners to be easily installed or removed, as the threads enable the fasteners to be screwed or unscrewed with a simple rotational motion
• Offering a wide range of options for the fasteners, as the threads can vary in size, pitch, shape, and direction, depending on the application

Threading can be done on various types of metal fasteners, such as screws, bolts, nuts, studs, and inserts. However, threading also involves some challenges, such as:

• Requiring precise measurements and calculations of the thread dimensions, to ensure compatibility and interchangeability of the fasteners and the mating parts
• Generating heat and friction, which can cause the fastener or the cutting tool to wear out or deform
• Creating chips or shavings, which can contaminate the fastener or the work environment, and require proper disposal

To overcome these challenges, it is important to use the appropriate cutting tool, such as a tap, a die, or a thread mill, as well as to lubricate and cool the fastener and the cutting tool during the threading process. It is also advisable to use a thread gauge or a micrometer to verify the accuracy and quality of the threads.

Grinding

Grinding is a secondary operation that is often performed on metal fasteners to improve their surface quality. It involves using an abrasive wheel or a belt to smooth or polish the surface of the fasteners, removing any burrs, sharp edges, or irregularities that may affect their performance or appearance. Grinding can provide several benefits, such as:

• Increasing the durability and reliability of the fasteners, as the smooth surface reduces the risk of cracking, corrosion, or fatigue
• Enhancing the functionality and efficiency of the fasteners, as the smooth surface reduces the friction and noise during operation
• Improving the aesthetics and value of the fasteners, as the smooth surface gives them a shiny and professional look

Grinding can be done on various types of metal fasteners, such as screws, bolts, nuts, washers, and pins. However, grinding also poses some challenges, such as:

• Requiring careful control and adjustment of the grinding speed, pressure, and direction, to avoid overheating, burning, or scratching the fastener or the abrasive wheel
• Generating heat and dust, which can cause the fastener or the abrasive wheel to wear out or deform
• Creating sparks or flames, which can pose a fire or explosion hazard, and require proper ventilation and safety measures

To overcome these challenges, it is important to use the appropriate abrasive wheel or belt, such as a grinding wheel, a sanding belt, or a polishing pad, as well as to lubricate and cool the fastener and the abrasive wheel during the grinding process. It is also advisable to use a magnifying glass or a microscope to inspect the surface quality of the fasteners.

Plating

Plating is a secondary operation that is often performed on metal fasteners to enhance their corrosion resistance, electrical conductivity, or appearance. It involves coating the fasteners with a thin layer of metal or alloy, such as zinc, nickel, chrome, or gold, using either an electroplating or an electroless plating method. Plating can offer several advantages, such as:

• Protecting the fasteners from rust, oxidation, or chemical attack, extending their service life and reducing maintenance costs
• Improving the electrical performance of the fasteners, increasing their conductivity, solderability, or shielding ability
• Beautifying the fasteners, adding color, luster, or texture to their surface, making them more attractive and appealing

Plating can be done on various types of metal fasteners, such as screws, bolts, nuts, washers, and clips. However, plating also involves some challenges, such as:

• Requiring careful preparation and cleaning of the fastener surface, to ensure a good adhesion and uniformity of the coating
• Generating hazardous waste and emissions, which can harm the environment and human health, and require proper treatment and disposal
• Increasing the cost and complexity of the fastener production, as the plating process requires specialized equipment, materials, and skills

To overcome these challenges, it is important to use the appropriate plating method, such as electroplating or electroless plating, as well as to follow the environmental and safety regulations and standards during the plating process. It is also advisable to use a thickness gauge or a spectrometer to measure the quality and composition of the coating.

Painting

Painting is a secondary operation that is often performed on metal fasteners to change their color, texture, or reflectivity. It involves applying a layer of paint or powder to the fasteners, either by spraying, dipping, or brushing. Painting can provide several benefits, such as:

• Customizing the fasteners, matching them to the color scheme or design of the project, making them more appealing and distinctive
• Shielding the fasteners, reducing their exposure to sunlight, heat, or moisture, increasing their durability and resistance
• Marking the fasteners, identifying them by size, type, or function, facilitating their installation and maintenance

Painting can be done on various types of metal fasteners, such as screws, bolts, nuts, washers, and clips. However, painting also poses some challenges, such as:

• Requiring careful preparation and cleaning of the fastener surface, to ensure a good adhesion and coverage of the paint or powder
• Generating volatile organic compounds (VOCs) or dust, which can affect the air quality and human health, and require proper ventilation and protection
• Increasing the drying and curing time of the fasteners, delaying their delivery and use

To overcome these challenges, it is important to use the appropriate paint or powder, such as acrylic, epoxy, or polyester, as well as to follow the application and curing instructions during the painting process. It is also advisable to use a colorimeter or a gloss meter to assess the appearance and quality of the paint or powder.

 Conclusion

Secondary operations on metal fasteners are additional processes that can enhance the performance and appearance of the fasteners, depending on the desired outcome. Some of the most common secondary operations are drilling, threading, grinding, plating, and painting. Each of these operations has its own benefits and challenges and requires careful planning and execution. By choosing the right secondary operation for your metal fasteners, you can achieve your project goals and satisfy your customers.

Delta Secondary are experts in secondary operations for your parts. Contact us today to discuss your requirements or just get some advice.