Non-Standard Carbon Steel Square Screws

Product introduction

This product is a typical non-standard screw. The shaft adopts a square columnar structure. The head can be equipped with round head, countersunk head, etc. according to the requirements. It has both high torque transmission and anti-rotation functions. As a special-shaped screw, its integrated molding design has high strength and is suitable for scenarios such as machinery manufacturing, automation equipment, and automotive parts that have special requirements for fastening reliability.

 

The product is made of high-quality carbon structural steel, and can provide various surface treatments such as galvanizing, blackening, and Dacromet, with performance levels ranging from 4.8 to 12.9. We focus on customized non-standard screw solutions and strictly implement quality control from drawing review to precision processing to ensure that dimensional accuracy and mechanical properties meet customer requirements. Supports small batch samples and large batch supply, welcome to customize drawings.

 

Product design and features

Carbon steel square screws are a typical non-standard screw. The shaft adopts a square columnar structure, which is different from common hexagonal head or round head screws. This product belongs to the category of special-shaped screws. Its main features include:

Square column design: Provides a large torque transmission area, is not easy to slip during installation, and is suitable for high-torque fastening scenarios;

Diversified structure: round head, countersunk head, gasketed head, etc. can be configured according to needs, and the head can be equipped with a slot, cross slot or internal hexagonal drive method;

Anti-rotation function: After the square shaft is matched with the mounting hole, it can effectively prevent the screw from rotating during use, which is especially suitable for assembly environments that require positioning and anti-loosening;

Integrated molding: made of whole body by cold heading or turning, with high strength and no welding weak points.

As a special-shaped screw, its appearance and function completely break through the limitations of standard fasteners and can meet various non-standard connection needs.

 

Materials and application fields

Carbon steel square screws are made of high-quality carbon structural steel (such as 10#, 45#, 35K, etc.), and different surface treatments can be selected according to the use environment:

Galvanized/nickel plated: Provides good rust resistance and is suitable for general industrial environments;

Blackening/Phosphating: Suitable for occasions where anti-corrosion requirements are not high but anti-glare is required;

Dacromet/hot-dip galvanizing: suitable for outdoor or humid environments with high anti-corrosion requirements.

As non-standard screws, they have a wide range of applications:

Machinery manufacturing: used for positioning and fastening in machine tools and fixtures;

Building hardware: such as curtain wall connectors and special-shaped screws in steel structure nodes;

Automation equipment: used in scenarios such as guide rail fixing and slider limiting;

Auto parts: used for non-standard connection parts around the chassis and engine;

Electronics and communications: widely used in the internal structure of precision equipment that requires anti-rotation.

 

Quality control and certification system

Since carbon steel square screws are customized non-standard screws, their production process implements a strict customized quality control system:

Drawing review: Each special-shaped screw undergoes structural and process feasibility evaluation before being put into production;

Raw material control: All carbon steel materials come with material certificates to ensure that the ingredients meet standards;

Dimensional accuracy control: Key dimensions (square edges, diagonals, length, thread accuracy) are fully inspected or randomly inspected using digital testing equipment;

Mechanical property testing: including tensile strength, hardness, and torque testing to ensure that the performance level specified by the customer is met (such as level 4.8, level 8.8, etc.);

Surface quality inspection: coating thickness, salt spray test, etc. are carried out according to standards;

System certification: The company has passed ISO 9001 quality management system certification, and automotive products can meet the requirements of IATF 16949, ensuring that each batch of non-standard screws has complete traceability.

 

Customized services

We focus on providing customers with customized non-standard screw solutions. The customized range of carbon steel square screws includes:

Size customization: Square-to-side dimensions, square length, total length, thread specifications and length can all be customized according to customer drawings or samples;

Head type customization: Optional round head, countersunk head, T-shaped head, head with gasket, etc., and drive slots (square, cross, inner hexagon, plum blossom slot, etc.) can be added;

Thread form: full thread, half thread, or non-standard tooth type can be designed;

Performance level customization: According to strength requirements, different performance levels such as level 4.8, level 8.8, level 10.9, and level 12.9 can be provided;

Surface treatment customization: choose galvanizing, nickel plating, blackening, phosphating, Dacromet, hot dip galvanizing, etc. according to anti-corrosion requirements;

Packaging method: Bulk, bagged, pallet packaging or customized labels can be provided to meet the needs of different assembly lines.

Whether it is small batch sample verification or large batch stable supply, we can respond quickly to ensure that each customized non-standard screw accurately matches the customer's assembly process and usage environment.

 

FAQ

Q: Are carbon steel square screws standard parts?

A: No. Square screws are non-standard screws. There are no unified standard specifications on the market. They need to be customized and produced according to the drawings or specific requirements provided by the customer.

 

Q: Why is it called a "specially shaped screw"?

A: Because its shaft is square-cylindrical, which is obviously different from standard shapes such as conventional hexagonal heads, round heads, and pan heads. It is a typical special-shaped screw that has both tightening and anti-rotation functions.

 

Q: What is the anti-corrosion capability of carbon steel?

A: Carbon steel itself is easy to rust, but the corrosion resistance can be significantly improved through surface treatments such as galvanizing, nickel plating, and Dacromet. The salt spray test time can be controlled from 24 hours to 1000 hours according to customer requirements.

 

Q: As a customized non-standard screw, what is the minimum order quantity?

A: The minimum order quantity depends on the complexity of the product and the production process. When using the cold heading forming process, it is recommended that the minimum order is 3000-5000 pieces; when using CNC turning or centering machine processing, small batch customization of dozens to hundreds of pieces can be supported.

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