Machine Thread Three-piece Combination Screw

The machine thread three-piece combination screw represents a highly integrated fastening solution. It consists of a machine screw, a flat washer, and a nut pre-assembled into a single, ready-to-use unit. The core advantages of this assembly are integrated construction, elimination of separate part handling, and uniform clamping force. Manufactured in accordance with ISO 14583 standards, the three components are precision-matched: the screw features a 6g-grade thread, while the nut uses a 6H-grade thread, ensuring perfect thread engagement. The washer is typically a standard flat washer. Once assembled, the unit remains secure with no loosening or separation, allowing direct use straight out of the box. This significantly reduces part sorting and matching time, making the product ideal for large-scale, standardized hardware assembly applications.

Machine thread three-piece combination screws are widely used in batch assembly of construction machinery, construction hardware installation, home appliance production lines, automotive component assembly, and mass production of medical devices. In construction machinery, they secure frames and hydraulic systems, with the integrated combination ensuring assembly consistency and equipment reliability. For construction hardware such as door and window frames and railings, they enable rapid fastening and reduced installation costs. On appliance production lines for air conditioners and televisions, they accelerate the assembly of core components, increasing production output. In medical device manufacturing, including rehabilitation equipment, the standardized assembly ensures product uniformity. As such, the product is a key component in large-scale, standardized assembly operations.

These combination screws are available as complete sets made from carbon steel 1035A (screw, nut, and washer), full stainless steel 304, or high-strength alloy steel 40Cr. The carbon steel set meets the 8.8 strength grade for general high-strength applications. The stainless steel set provides excellent corrosion resistance for special environments, while the alloy steel set achieves a 10.9 strength grade for heavy-duty assemblies. Surface treatments include zinc plating (ASTM B633), nickel plating (ASTM B733), and passivation for stainless steel, with salt spray resistance ranging from 72 to 120 hours. Certified to ISO 9001 and IATF 16949 (automotive) standards, the assembly clearance is controlled within ≤0.03mm. Custom configurations are available, including different head types, washer styles (spring or serrated), extended lengths, and special coatings. Packaged in boxes of 500–1,000 sets with specification and inspection reports, each machine thread three-piece combination screw set guarantees precise fit and reliable performance.