Socket Screws Offer Weight-saving Benefits
People are starting to see socket screws used more and more in everyday mechanical uses, especially where weight and strength are a structural concern. Engineers acknowledge the benefits of using these fasteners. They offer superior torque and holding power for their size and weight. This weight reduction means they can be specified for use in applications where saving weight is crucial. They can also be fastened by using commonly-available tools.
Socket head screws were invented in the 1860s to 1890s but were not widely manufactured until around 1910. A Canadian engineer named Peter L. Robinson first mass-produced a square drive socket-type screw in 1908, having patented a manufacturing method for light, low-strength screws. The square drive was never commonly used because mechanics and manufacturers had problems quickly inserting the tools into the tops of the screws. There were only four specific directions that the screws would accept the tools.
Change to the Hexagon Shape
William G. Allen invented and patented a method of cold-forming screws with hexagonal drive shapes. The "Allen safety set screw" manufactured by the Allen Manufacturing Company of Hartford, Connecticut, was the first mass-produced socket screw. Allen's name soon became synonymous with the simple and logical fastener, which became a global standard.
Simply adding two sides to the resulting hexagon shape of the recessed drive allowed the drive tools to be inserted from a number of angles, unlike the square drive screws. This allowed mechanics to greatly speed up the application and removal of these fasteners. and this reduced the manufacturing time which increased the profits.
Around 1911, Howard T. Hallowell of the Standard Pressed Steel (SPS) Company independently developed a version of the hexagon socket drive set screw. With more and more manufacturers embracing the hexagon as their preferred drive shape, it seemed like these fasteners were going to revolutionize manufacturing. The headless set screws with the internal drives were less likely to catch on the clothing of workers and pull them into rotating machinery.
Manufacturers and engineers were starting to realize the benefits of housing the drive receptacle in the tops of the screws.
Trend Towards Smaller Applications
As the machining capabilities of manufacturers continued to expand and grow throughout the 20th century, miniaturization became a trend. Designers and engineers were looking for a way to save weight, particularly in the new automotive industry. As automobile sophistication increased, the industry continued to add new features to their vehicles, and saving weight and space became crucial in keeping the vehicle's handling and fuel economy manageable.
At the same time, more strength was required from the fasteners used in industry. As more forces were subjecting these smaller machine parts to greater stress, more torque was needed from the fasteners used in these applications.
Greater Strength and Faster Application
The superior benefits of screws with hexagon-shaped internal drives were soon realized. By having the drives on the tops of the screws, the length of the drive could be extended down through the shaft of the screw itself. This provided more surface area for the driving tool to contact. This added surface area translated into a greater amount of torque that the screw could withstand and a greater amount of holding strength it could provide to the finished piece of machinery.
Designers and engineers also realized another benefit associated with the benefit of additional holding strength. Less of the fasteners had to be used in a given application. This provided additional benefits for the manufacturers in that the parts would be lighter. The parts would also be quicker to manufacture with fewer fasteners to be attached.
The overall cost of producing the parts would also be reduced to reflect the reduction in the number of fasteners, production time, and shipping weight.
Expanded Applications
As the multiple benefits afforded by these fasteners began to be recognized, more and more designers and engineers incorporated them into the plans of a widening variety of industrial applications. Flat head cap screws were developed for applications that needed strong fasteners while also having a perfectly flush surface. These screws are highly prized in the aviation industry for their strength and adaptability.
Button head cap screws were created for screws that needed to maintain a smooth surface so that external moving parts wouldn't catch on. As engineers soon realized the value of creating specialized screws for different applications, flange head cap screws were also developed. These screws added a bit of extra surface area around the screw, which was beneficial in holding thin sheet metals and plastics and the set screw that was originally created by the SPS company still remains useful to this day.
What Willian Allen and Howard Hallowell created so many years ago is regularly still the most efficient and robust fastener available in the world. Hanshin Neji (Thailand) provides a range of all types of socket screws to serve the manufacturers of Thailand. We have a fastener that will suit your application.
