Torx Cylindrical Head Screw

The Torx cylindrical head screw is a common mechanical connection fastener. The following is the relevant introduction to the Torx cylindrical head screw:

Structural Features of the Torx Cylindrical Head Screw

Torx Slot: Located on the head of the screw, it is designed as a Torx-shaped groove. This groove type fits closely with a dedicated Torx screwdriver, enabling precise torque transmission. It can effectively prevent the screwdriver from slipping during operation, withstand a large tightening torque, and ensure smooth installation and disassembly as well as the fastening effect of the screw.

Cylindrical Head: The head is cylindrical, with a flat circular top surface and a vertical cylindrical side surface. The design of the cylindrical head makes the contact area between the screw head and the connected part relatively small. However, in some specific situations, such as when a smaller head space is required or there are special requirements for the appearance of the connection point, the cylindrical head screw is more applicable. It can provide a more concentrated fastening force and is suitable for use in some mechanical equipment or electronic products with high space requirements.

Threaded Part: Similar to the threads of ordinary screws, it is used to achieve a tight connection by matching with the corresponding nut or threaded hole. There are various specifications and precisions of threads, and common ones include coarse threads and fine threads. Coarse threads are suitable for general fastening connections and can withstand a large axial tensile force; fine threads are used in situations where higher tightening precision and a smaller preload force are required.

Specification Dimensions of the Torx Cylindrical Head Screw

Thread Diameter: There are various specifications, such as M2, M2.5, M3, M4, M5, M6, M8, etc. Here, "M" represents the metric thread, and the following number indicates the nominal diameter of the thread, with the unit being millimeters. When choosing, an appropriate diameter should be determined according to factors such as the thickness of the connected parts and the force-bearing conditions. Generally speaking, for connections that bear a large tensile or shear force, screws with a larger diameter should be selected.

Screw Length: The length range is relatively wide. Common lengths include 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 30mm, etc. The selection of its length should comprehensively consider factors such as the total thickness of the connected parts, the thickness of the washer, and the thickness of the nut to ensure that there is enough thread length for the screw to match the nut after tightening, and the head can closely fit the surface of the connected part.

Application Fields of the Torx Cylindrical Head Screw

Electronic Equipment Manufacturing: It is often used in the production of electronic equipment, such as the assembly of mobile phones, tablets, laptops, etc. The cylindrical head design can provide a fastening function within a limited space, and the Torx slot can ensure that the screw will not be damaged due to slipping during multiple disassembly and assembly processes, ensuring the stability and reliability of the equipment.

Precision Instrument Manufacturing: It is used for the connection of components of various precision instruments, such as optical instruments, measuring instruments, etc. The Torx cylindrical head screw can withstand a certain torque and tensile force, meeting the precision requirements of precision instruments during operation and ensuring the normal operation of the instruments.

Small Mechanical Manufacturing: In some small mechanical equipment, such as small motors, reducers, office equipment, etc., it can be used to connect various components. Its structural features enable it to provide a reliable connection in situations with limited space. At the same time, the Torx slot design facilitates installation and disassembly, improving the maintainability of the equipment.

Model Making: In the field of model making, such as aviation models and car models, Torx cylindrical head screws are often used to connect the various parts of the models. Due to its small head, it will not affect the appearance of the model, and it has a good fastening effect, making the model structure more stable.

Materials and Surface Treatments of the Torx Cylindrical Head Screw

Materials

Carbon Steel: It has high strength and hardness and a relatively low cost. After appropriate heat treatment, it can obtain good mechanical properties and is suitable for general fastening connection occasions, such as ordinary small machinery, model making, etc.

Stainless Steel: It has excellent corrosion resistance and oxidation resistance. Common materials include 304 and 316, etc. 304 stainless steel has strong versatility and is suitable for most general corrosive environments; 316 stainless steel, due to the addition of molybdenum elements, has better corrosion resistance and pitting corrosion resistance and is often used in electronic equipment with high corrosion resistance requirements or small machinery used outdoors.

Alloy Steel: It has higher strength, toughness, and wear resistance and is often used in high-end precision instruments with strict requirements for screw performance or small machinery in special environments to meet the usage requirements under high-strength, high-impact or special working conditions.

Surface Treatments

Galvanizing: A zinc layer is formed on the surface of the screw through electroplating or hot-dip galvanizing, which can improve corrosion resistance. The zinc layer will form a dense zinc oxide protective film in the air, preventing oxygen and moisture from coming into contact with the screw substrate and preventing rust. Common types include white zinc, multicolored zinc, black zinc, etc. The different colors are due to different surface passivation treatments, and their corrosion resistance also varies.

Nickel Plating: Plating nickel on the surface of the screw can improve corrosion resistance and wear resistance, and at the same time, make the surface have a good gloss. Nickel-plated screws are often used in fields with high requirements for appearance and corrosion resistance, such as electronic equipment, precision instruments, etc.

Blackening: Also known as bluing treatment, it is to form a black oxide film on the surface of the screw through chemical oxidation. The screw after blackening treatment has a certain rust prevention ability and a beautiful appearance, and is often used in small machinery or models with appearance requirements. However, its corrosion resistance is relatively weak and is suitable for indoor or dry environments.

Installation and Disassembly of the Torx Cylindrical Head Screw

Installation: First, pass the screw through the hole of the connected part, and then use a Torx screwdriver to screw the screw into the corresponding nut or threaded hole. When tightening, control the torque well to ensure that the screw reaches an appropriate preload force. Ensure that the Torx screwdriver fits the slot completely to prevent slipping, which may damage the slot or affect the fastening effect.

Disassembly: Use the corresponding Torx screwdriver to loosen the screw. If the screw is rusted or difficult to disassemble, methods such as using a rust remover or heating can be used to reduce the friction between the threads. If the Torx slot is damaged and the screw cannot be disassembled normally with a screwdriver, you can try to drill off the head of the screw with an electric drill and then remove the remaining part. However, be careful during the operation to avoid damaging the connected part.