Selection Guide for Automotive Combination Screws

Although automotive combination screws are small in size, they are key components that ensure the safety and performance of the entire vehicle. They are widely used in core parts such as engines, chassis, and interiors, and play a crucial role in fastening and connecting. Choosing a reliable screw supplier is an indispensable guarantee in your automotive manufacturing process.

I. Common Types and Applicable Scenarios

Cross head combination screws: The design of a disc head with a flat washer and a crosshead groove is cost-effective and highly efficient in installation. They are suitable for non-load-bearing scenarios such as interior assembly and wire harness fixation. The type of screws we produce are made with high-precision stamping technology. The cross grooves are evenly force-bearing, avoiding thread slippage during installation. We have provided stable supplies to many interior suppliers of car manufacturers.

Hexagon socket combination screws: Cylindrical head with hexagonal hole structure, can be used in conjunction with professional wrenches to achieve precise torque control. They have excellent torsional resistance and sealing performance, making them an ideal choice for high-strength connection parts such as engine mounts and chassis. Through a special heat treatment process, we ensure that the tensile strength of our products precisely matches the 10.9/12.9 grade standards. Each batch undergoes torque testing to guarantee long-term stable force application after installation.

Flange combination screw: The head is integrally formed with a flange surface and anti-slip teeth design, featuring a large contact area and outstanding anti-loosening effect. It is suitable for high-frequency vibration environments such as wheel hubs and braking systems. Our flange surface processing is precisely turned by CNC lathes, with strict control over the depth and spacing of tooth patterns. The salt spray test can last for over 300 hours, far exceeding the industry's conventional standards, making it more reliable in dealing with complex road conditions.

Nylon locking combination screw: The threaded end is embedded with a high-elasticity nylon ring, which effectively prevents loosening through friction and has excellent vibration resistance.

Ii. Key Performance and Standards

Strength grade: General components are compatible with 8.8 grade (tensile strength ≥800MPa); The key components such as the chassis and engine need to be of grade 10.9/12.9 (tensile strength ≥1000-1200MPa). All of our products are manufactured in accordance with the IATF16949 quality management system. Their strength grades can be certified by third-party testing institutions. Each batch of products comes with a test report, allowing you to use them with peace of mind.

Rust prevention treatment: Electro-galvanizing (low cost, suitable for dry environments); Dacromet (strong corrosion resistance, salt spray test ≥240 hours, compatible with chassis and engine compartment) Hot-dip galvanized/stainless steel (suitable for highly corrosive and high-load environments). Anti-rust solutions can be customized according to your usage environment. The salt spray test time can be adjusted as needed to meet the strict requirements of different vehicle models.

Torque and anti-loosening: It must comply with international standards such as ISO 7380 and DIN 7984. A torque wrench must be used during assembly. The anti-loosening performance needs to pass professional vibration tests. We can provide you with exclusive torque matching suggestions to help you avoid safety hazards caused by improper assembly.

Iii. Selection and Key Points for Use

Select the type based on force: For load-bearing components (such as suspensions and engines), priority should be given to choosing Allen screws, flanges or high-strength screws. For non-load-bearing components (such as interiors and wiring harnesses), economical and practical crosshead screws can be selected. Our technical team can provide you with a free selection plan based on your component drawings and force analysis, avoiding excessive selection that increases costs or insufficient selection that affects safety.

Adapt to the environment: In high-temperature areas (such as around the engine), nylon screws should be avoided. It is recommended to use metal locks or flange types. For damp/corrosive environments (such as the lower part of the chassis), Dacromet treatment or stainless steel material is recommended. We can provide professional assembly suggestions based on the usage environment of your product to help you assemble it better.

As a manufacturer specializing in automotive assembly screws for 30 years, Yuhuang Fasteners has not only passed the IATF16949 certification but also holds multiple national utility model patents. It has served over 200 automotive parts enterprises and can provide 24-hour rapid quotations and 15-day customized development.

From the initial selection consultation, free sample testing, to mass production and delivery, and after-sales technical support, we offer a "one-stop" service, allowing you to avoid having to deal with multiple suppliers. If you have any product requirements or technical questions, you can contact us by email at any time. We will respond within 24 hours and provide you with professional solutions.

Consult the customized plan immediately and get the exclusive quotation!

Yuhuang Technology Lechang Co., LTD

Email: [email protected]

WhatsApp/WeChat/Phone: +8613528527985