A screw is a type of threaded fastener much like a bolt or stud and they come in a variety of drive types and heads to fit a wide range of applications. The two main types of screws are machine and wood screws whose threads orients in either left or right direction. In addition, the threads can be tapered, straight or parallel. Both machine and wood screws are made of metal, but the wood screw is tapered and form their thread to the actual component material being fastened while the machine screw joins with nuts.
History of Small Metal Forming Screw
The idea of the screw goes back to around 200 B.C. and this is the period where screws had to be handmade, meaning there were now two screws that were uniform. However, it’s in 1928 that saw the standardization of screw threads by the National Screw Thread Commission. This allowed screws to be used made and used interchangeably.
Today, the process of making screws has been replaced by thread rolling, which is the primary method used to make strong, smooth, precise bolts and other fasteners. This technique was introduced back in 1836 by American Willian Keane, however, it wasn’t embraced that much due to low-quality iron metal that was used to produce the thread rolled screws.
The screws made then split easily when subjected to the die-cutting process. It’s the demand to mass produce screws at a relatively low cost that led to the reevaluation and growth of the thread-rolling manufacture of screws.
Raw Materials
Small metal forming screw like most screws are made from carbon steel wire, however, steel is the most common raw material for making nuts, bolt and other fasteners. Other metals such as nickel alloys, brass or aluminum alloys can also be used. While extra protection can be added to fasteners by adding a layer of coat such as nickel, zinc, cadmium or chromium, the quality of the metal used is of paramount importance to avoid cracking in the first place.
Screw Design
In the screw design process, the two most important things to note are lead and pitch. Lead is defined as the linear travel the nut makes per one screw revolution while the pitch is basically the distance between the screw threads from the exact point on each thread.
How are small metal forming screws made
Custom screws and those miniature screws are made through a process called machining. It is a highly expensive process of making small metal forming screw but it ensures preciseness when crafting variations in screws. Other than the high cost of production, machining process takes a lot of time, unlike thread-rolling which is used in mass production. Though the head creation and thread cutting of custom screw is much similar to the standard screw, more precise machine is needed to get the job done with no errors.