What are the Production Processes for Precision Small Screws

Behind some small products that we often overlook, ranging from eyeglasses to airplanes, lies a tiny yet indispensable element - screws. A good screw cannot be made without a good processing method, whether it's a tiny 1.0 precision screw used in precision instruments or a large, ultra-long screw used in wind turbines or airplanes. So, what are the production processes for precision small screws?

Precision electronic screws generally require electroplating. As we know, these electronic screws are very small, making the electroplating process challenging. If the quantity is small, the electroplating factory may mix different specifications of precision screws together for electroplating, resulting in some areas not being plated properly. This can easily lead to product scrap. Before electroplating, we must clean the precision electronic screws thoroughly and work with a reliable electroplating factory to achieve perfect electroplating.

When electroplating small electronic screws, they should not be mixed with rigid items that may affect the quality of the screws:

Firstly, it is difficult to meet the quality requirements of electroplating for different screws under conventional electroplating conditions.

Secondly, the specifications of hardware screws can be too similar, with sizes and lengths appearing almost identical. Larger screws, such as outer hexagon bolts, should be electroplated separately. Otherwise, they will be difficult to separate and screen after electroplating.

Thirdly, heavier screws and lighter screws, smaller screws and larger screws should be electroplated separately. Otherwise, they may collide during the electroplating process, causing damage to the screws.

Fourthly, screws that are prone to getting stuck together should be electroplated separately. Otherwise, screws of different specifications and models may get stuck together during electroplating, making it difficult to electroplate. Even after electroplating, it will be difficult to separate these two types of screws.

Thread cutting generally refers to the method of processing threads on workpieces using formed tools or abrasives, including turning, milling, tapping, threading, grinding, lapping, and whirlwind cutting. When turning, milling, and grinding threads, the transmission chain of the machine tool ensures that the turning tool, milling cutter, or grinding wheel moves accurately and uniformly along the axial direction of the workpiece for one pitch per revolution of the workpiece. When tapping or threading, the tool (tap or die) and the workpiece perform relative rotational motion, and the previously formed thread groove guides the tool (or workpiece) to move axially.

Thread rolling is a processing method that uses a formed rolling die to plastically deform the workpiece to obtain threads, also commonly known as cold heading in the industry. Machines used in this production method include single-die machines, multi-station machines, and die-casting machines. Screws produced by this method have faster production speeds and lower costs. However, compared to cutting processes, the heads and tails of screws produced by this method are naturally formed, with a rounded appearance rather than sharp edges and corners like those produced by cutting processes.

Each method has its own benefits. Although the speed of the cutting process is slower than that of cold heading, it offers higher precision. In contrast, the cold heading process produces more and faster with lower costs, especially when producing precision small screws. In such cases, the cost-effectiveness of the cold heading process is higher than that of the turning process.