Combination Screw with Spring Washer

The Combination Screw with Spring Washer comes pre-assembled, ready to use. The spring washer is already installed, so there is no need to add it separately. The washer prevents loosening by applying constant tension; even when your machine vibrates, the screw stays tight. This screw is commonly used on engine covers, motor bases, vibrating screens, and farm machinery. One client manufactured vibrating screens that shook thousands of times per minute. Normal screws came loose after just two hours, but our Combination Screw with Spring Washer maintained constant tension and never loosened. It is now standard on all their equipment.

Diameters range from φ2 to 10 mm, with lengths from 4 to 40 mm. Materials include 10B21, 35#, 45# steel, SUS304, and SUS430. Surface finishes include zinc, nickel, chrome, Dacromet, phosphate, passivation, and black oxide. The screw and washer are pre-assembled; the washer will not fall off or get stuck. Our screws comply with GB/T 3098.1-2024. Strength grade is typically 8.8, with tensile strength ≥800 MPa and yield strength ≥640 MPa. Thread precision is 6g, and all screws pass go/no-go gauge inspection. We perform transverse vibration tests, and preload loss remains below 10%. Hardness for grade 8.8 screws is HRC 22–32. Salt spray resistance: standard zinc plating lasts 48 hours without white rust, and outdoor-grade finishes exceed 72 hours. Our optical sorter removes defective screws automatically.

We ensure on-time delivery by providing realistic lead times and sticking to production plans. Each step-cold heading, thread rolling, heat treatment, surface finishing-is supervised. Core raw materials are kept in stock, and for major clients, production capacity is reserved. Stock items ship quickly, regular mass production takes about one week, and large orders usually ship within one month. Repeat orders are faster since molds and parameters are already set. We provide a 12-month warranty; any material or workmanship failure is replaced free of charge. Our products are trusted by customers across Southeast Asia, the Middle East, and Europe.