Machine screws

The specifications of machine screws usually include nominal diameter, pitch, head type, length and other parameters. The specifications of machine screws can be detailed from the following aspects:

1. Nominal diameter and pitch:

Metric machine screws are usually specified with "M" followed by a number to indicate the nominal diameter in millimeters. For example, M3 indicates a nominal diameter of 3 mm, and M4 indicates a nominal diameter of 4 mm.

Thread pitch (i.e. the axial distance between adjacent threads) is also expressed in millimeters. For example, M3x0.5 means a nominal diameter of 3 mm and a pitch of 0.5 mm.

2.Head type:

Common head types include cylindrical head, semi-countersunk head, countersunk head, spherical cylindrical head, pan head, semicircular head, hexagonal head, etc.

The choice of head type depends on the installation environment and stress conditions. For example, the cylindrical head is suitable for situations where a larger head space is required, while the countersunk head is suitable for situations where the head needs to be hidden.

3. Length:

The length of the screw is usually two to three times the nominal diameter, but the specific length needs to be determined according to the actual application requirements.

For screws longer than three times the nominal diameter, the thread length may extend to two pitches adjacent to the head surface.

4.Material and grade:

The materials of machine screws usually include low carbon steel, medium carbon steel, etc., and some high-strength screws are made of stainless steel.

Hardness grade such as HRB69-100 or HRC25-38, etc. Choose the appropriate hardness grade according to the specific application.

5.Standards and naming methods:

The ISO standard adopts the naming method of "M+diameter+step". For example, M6x1.0 means a metric thread with a diameter of 6 mm and a pitch of 1.0 mm.

The ANSI/ASME standard adopts the naming method of "# + diameter + UNC/UNF". For example, #8-32UNC represents a coarse thread model with a diameter of 1/8 inch and a pitch of 32 TPI. The specifications of machine screws involve multiple parameters, including nominal diameter, pitch, head type, length, material and grade, etc. Proper understanding and selection of appropriate machine screw specifications is critical to ensuring the strength and stability of the joint.

Every style and size is in stock, and special size stainless steel screws are available for customization.

High strength and shock resistance: Machine screws are usually made of high-strength materials, which can withstand large mechanical stress and have good shock resistance.

Precision design: The thread design of the machine screw is precise to ensure the tightness and stability of the connection. It is suitable for occasions that require precise and stable connection.

Easy to disassemble and reuse: Machine screws are reusable and easy to disassemble, suitable for mechanical equipment that require regular maintenance and replacement.

Wide range of applications: From household appliances to industrial machinery, machine screws are suitable for almost all occasions that require precise and stable connections.

Various head shapes and material options: Machine screws have a variety of head shapes (such as flat head, round head, internal hexagon, etc.) and materials (such as stainless steel, brass alloy, etc.) to adapt to different application needs.

Suitable for heavy-duty applications: Machine screws are suitable for heavy-duty applications, provide strong structural support, are more versatile than set screws, and come in a wider range of sizes and materials. 

Mechanical equipment: Machine screws are often used to secure and connect components in mechanical equipment, such as motors, gears, and transmissions. They screw through pre-drilled threaded holes, ensuring the stability and security of the device.

Electronics: In electronic equipment, machine screws are used to secure circuit boards, casings, and other components. These screws often require a high level of precision to ensure proper functioning of electronic components.

Construction Engineering: Machine screws are widely used in building structures, such as the assembly of metal structures, the installation of doors and windows, and the fixation of electrical junction boxes.

Automotive Industry: In automobile manufacturing, machine screws are used to secure engine components, body panels, interior accessories, and various mechanical components.

Furniture industry: Machine screws are also widely used in the assembly of wooden and metal furniture, such as the fixation of table or chair legs, the installation of hinges and handles.

Food Processing and Medical Equipment: Stainless steel machine screws are commonly used in food processing equipment and medical equipment due to their corrosion resistance and high strength properties.

Aerospace: Machine screws also play an important role in the aerospace field, used to fix and connect various precision components.

Flat head screws:

lApplications: Home decoration, woodworking equipment, automobile manufacturing, industrial machinery.

lInstallation method: Use a screwdriver to screw into the hole.

lAdvantages: It is beautiful, safe, wear-resistant, easy to install and has a wide range of uses.

Round head screws:

lApplication: Suitable for medical equipment, wind energy, aerospace, office equipment, petrochemical industry, electronics, communications, ships and other fields.

lInstallation method: After pre-drilling the hole, use a screwdriver or wrench to screw the screw into the pre-drilled hole.

lAdvantages: Not easy to damage external components, has a variety of driving methods, has corrosion resistance, high strength and reliability, is beautiful and practical.

Phillips pan head screws:

lApplication: Machinery manufacturing, automobile manufacturing, electronic equipment, furniture manufacturing, construction decoration.

lInstallation method: Use an electric wrench to tighten the screws.

lAdvantages: Easy to tighten, high strength, corrosion resistance, quick installation, strong load-bearing capacity.

Machine screws:

lApplications: Electronic equipment, precision machinery, solar photovoltaics, Bluetooth headsets.

lInstallation method: Insert the machine screws into the tapped holes, and then tighten with appropriate tools (such as slotted, Phillips or Allen wrenches).

lAdvantages: strong bonding force, saving construction time, accurate torque, easy adjustment, and ensuring locking quality.

Custom machine screws:

lApplication: Designed for specialized applications requiring unique specifications.

lInstallation method: Customized installation according to specific application requirements.

lBenefits: Customized specifications to meet unique project needs, ensuring optimal performance.

Customization options:

Custom Sizes: We offer screws in standard and custom sizes to meet specific project requirements. Our advanced processing capabilities ensure a perfect fit for your application.

Material Selection: Depending on the application and environmental conditions, we offer screws made of stainless steel, galvanized steel, carbon steel and other specialty materials.

Surface Treatments: For enhanced corrosion resistance and durability, we offer a variety of surface treatments including galvanized, galvanized and custom coatings.

1. Material selection: Select appropriate materials based on required strength and environmental conditions.

2. Cutting: Cut the material into the desired shape and size.

3. Forging: Using high-pressure machinery to shape the bolts.

4. Threads: Create precise threads to ensure secure fastening.

5. Heat treatment: Enhance the strength and durability of bolts.

6. Surface treatment: Apply anti-corrosion coating.

7. Quality inspection: Ensure that each bolt meets strict quality standards.

8. Packaging: Pack completed bolts for shipment.

Global standards for machine screws mainly include the following:

ISO standards: Universal metric thread standards formulated by the International Organization for Standardization (ISO), such as ISO 4014, ISO 4015, ISO 4016 and ISO 4033, etc., covering standards for hexagonal head bolts, nuts and other fasteners.

American Standard (ANSI/ASME): Standards developed by the American Society of Mechanical Engineers (ASME) and the American National Standards Institute (ANSI), such as ASME B1.1, cover the unified inch thread system.

British Standard (BSW): British national standard, including Whitworth thread (BSW, BSF, BA), etc.

German Standard (DIN): German national standard, widely used in the European market.

Japanese Standard (JIS): Japanese industrial standard covering many types of screws and fasteners.

Common pairings of machine screws mainly involve the combined use of bolts, nuts, washers and other components. These components are usually selected and matched according to different application scenarios and requirements to ensure connection reliability and performance.

1. Bolts and nuts: This is the most common pairing method, usually using standard threaded connectors, such as hexagonal head bolts and hexagonal nuts. This pairing method is simple and widely used in various mechanical assemblies, with good connection reliability and easy disassembly.

2. Bolts and washers: Washers are used to increase the contact area, reduce stress concentration, or prevent wear caused by direct contact between bolts and the surface of parts. Commonly used washer types include flat washers, spring washers and butterfly washers.

3. Stud bolts and nuts: Stud bolts have threads on both ends and are suitable for occasions where axial force or torque needs to be transmitted. This pairing method can reduce assembly steps and improve connection efficiency.

4. Special pairing: For example, the combination of Torx screws and channel nuts under DIN standards is suitable for applications that require high precision and anti-loosening.

5. Thread grade matching: In mechanical assembly, the thread grades of bolts and nuts need to match to ensure good fit and prevent over-tightening or over-loosening. Common fit levels are H/g, H/h or G/h, among which 6H/6g is the recommended standard fit.

6. Anti-loosening device: In order to prevent threaded connections from loosening during work, anti-loosing devices such as locking nuts, spring washers, cotter pins, etc. are often used

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