In the realm of manufacturing and industrial processes, fasteners play a vital role in holding together various components. This article aims to shed light on different types of fasteners used in CNC (Computer Numerical Control) machining, their applications, and how they are produced.
1. What are Fasteners?
Fasteners refer to mechanical devices that are used to join or secure two or more objects together. These objects can include metal parts, plastics, wood, or any other material. They come in various shapes and sizes, each designed for specific applications where torque resistance, strength, and alignment are crucial factors.
2. Common Types of Fasteners:
a. Screws and Bolts:
Screws and bolts are one of the most commonly used fasteners in CNC machining. They have a threaded body with either a slotted head or hexagonal shape for tightening using screwdrivers or wrenches. The choice between screws and bolts depends on the requirement; screws provide clamping action, while bolts offer stronger shear force support.
Nuts are paired with bolts or screws to create a strong joint by providing additional thread engagement. They can be hexagonal, square, or cylindrical in shape, enabling easy grip during installation. Nuts come in different materials such as stainless steel, brass, aluminum, or nylon, depending on the application requirements.
Washers are thin flat plates with a hole in the center, placed under nuts and bolt heads to evenly distribute the load and prevent damage to the mating surfaces. They provide stability, reduce friction, and act as locking devices when combined with specialized washers like spring and lock washers.
Rivets are permanent fasteners used to connect two or more pieces of material by deforming and forming a fluid-tight seal. They require insertion through pre-drilled holes and can be expanded or compressed using specialized tools. They are commonly used in applications where welding or screwing is not feasible.
Pins, like cotter pins or dowel pins, provide more flexibility due to their ability to be easily inserted and removed. Cotter pins have two prongs that lock into place after insertion, while dowel pins ensure accurate alignment between components. Both types of pins offer crucial support and safety features for various CNC machining applications.
3. Production of Fasteners:
The production of fasteners involves several manufacturing processes such as forging, cold heading, turning, and threading. Here's a brief overview of the production steps involved:
a. Material Selection:
Fasteners can be made from different materials based on the desired strength, corrosion resistance, and application requirements. Common materials include stainless steel, carbon steel, brass, aluminum, and titanium alloys.
b. Cold Heading and Forging:
Wire or bar stock is turned into a blank by cutting it into the required length. Cold heading machines then deform the heated blank under high pressure to form the desired head shape. Forging follows a similar process but uses much higher temperatures to shape the material.
In this process, CNC lathes are utilized to cut threads or shapes onto the shank of the fastener, adding complexity or fine-tuning specific dimensions.
Threading involves creating helical grooves on the cylindrical body of the fastener. This operation can be performed through thread rolling (cold forming) or thread cutting methods, ensuring precise fitment with mating parts.
e. Surface Treatment:
Post-production, various surface treatments like heat treatment, plating (zinc, chrome, nickel), passivation, or coating may be applied to enhance the fastener's durability, appearance, and resistance against rust or corrosion.
Fasteners serve as the backbone in CNC machining, enabling the assembly and durability of countless products. Understanding the different types of fasteners, their applications, and production processes is essential to ensure proper selection and utilization in order to achieve robust and reliable connections between components. Whether it's screws, nuts, washers, rivets, or pins, each fastener type contributes to the strength and integrity of CNC machined parts.
By accurately choosing and incorporating suitable fasteners, manufacturers can uphold the quality and longevity of their CNC machined products. CNC Milling