CNC machining has revolutionized the manufacturing industry by offering precision and accuracy in creating complex parts and components. However, to ensure stability and durability, fasteners play a vital role in securely joining different elements together. This article will delve into various types of fasteners commonly used in CNC machining processes and their significance.
Screws are one of the most widely used fasteners due to their versatility. They come in different types such as machine screws, wood screws, self-tapping screws, and socket head cap screws. Machine screws are designed with pre-threaded holes within materials, while wood screws have sharp points and coarse threads for gripping wood effectively. Self-tapping screws create their own mating thread while being driven into the material. Socket head cap screws provide excellent strength and allow easy access with an Allen wrench-shaped tool.
Bolts are similar to screws but differ primarily in their usage. While screws typically go into tapped holes, bolts come with nuts and require plain or threaded holes for attachment. Hex bolts, carriage bolts, and anchor bolts are among the most common types. Hex bolts possess a hexagonal head and a threaded shaft, ideal for general-purpose applications. Carriage bolts feature smooth round heads and square necks, often utilized in outdoor furniture assembly. Anchor bolts have embedded ends specifically used in concrete structures.
Nuts are essential components that work hand-in-hand with bolts. They come in various shapes and designs, including hex nuts, lock nuts, wing nuts, and T-nuts. Hex nuts are the most prevalent type that offers maximum grip and torque efficiency. Lock nuts incorporate additional features like nylon inserts or deformed threads to prevent loosening due to vibrations. Wing nuts possess small "wings" on each side, providing quick manual installation without requiring tools. T-nuts are widely used in woodworking applications, as they slide into corresponding tracks to hold objects firmly.
Washers act as protective elements between fasteners and surfaces. They distribute the load evenly, prevent surface damage, and minimize loosening due to vibration or movement. Flat washers, spring washers, and lock washers are commonly utilized. Flat washers provide a smooth, uniform bearing surface while distributing pressure. Spring washers possess a slight bend that creates tension to eliminate bolt/screw loosening under dynamic loads or vibrations. Lock washers have serrations or teeth that bite into contact surfaces, enhancing grip and resistance to rotation.
Rivets are non-threaded fasteners often used when welding or screwing is not feasible. They consist of a cylindrical shaft with a head on one end. Upon installation, the opposite end is deformed to form a "bulb" shape, creating a secure and permanent joint. Blind rivets (pop rivets) are frequently employed in CNC machining because they can be set from one side only, making them convenient for tight spaces or inaccessible areas.
Threaded inserts reinforce weaker materials or allow threads where there were none previously. Helical coil inserts, key-locking inserts, and heat-set threaded inserts are common types. Helical coil inserts, also known as Heli-Coils, provide durable metal threads in softer materials like aluminum or plastic. Key-locking inserts offer stronger threads in tougher materials and critical applications. Heat-set threaded inserts function by melting the surrounding material slightly to securely embed the insert itself.
In the world of CNC machining, choosing suitable fasteners is crucial for achieving durable and reliable assemblies. Understanding the different types of screws, bolts, nuts, washers, rivets, and inserts allows manufacturers to make informed decisions that enhance efficiency and quality. By recognizing their unique characteristics and applications, CNC machining processes can benefit from the optimal use of fasteners for exceptional results. CNC Milling