Double Stack Self-Locking Washer
The Double Stack Self-Locking Washer is an advanced fastening solution designed to prevent loosening under vibration, shock, or dynamic loads. With a unique serrated surface and paired design, this washer ensures secure locking without additional adhesives or re-tightening. It is widely applied in automotive, aerospace, heavy machinery, wind power, and bridge construction projects, where safety and reliability are critical.
What Is a Double Stack Self-Locking Washer?
A double stack self-locking washer consists of two matched washers with interlocking serrations on the contact surfaces. When tightened, the serrations generate a wedge-locking effect that resists loosening caused by vibration or load variation.
Compared with conventional spring washers, this anti-loosening washer maintains preload more effectively and supports repeated installation without loss of locking performance, making it suitable for high-vibration fastening environments.
Production Process of Double Stack Self-Locking Washer
At Weforging, every Double Stack Self-Locking Washer is produced through a precise, multi-step process that ensures performance, strength, and durability.
Material Preparation – Premium alloy steel wire or billet is selected for its strength, ductility, and wear resistance. The material undergoes strict inspection before processing.
Cold Forging – Using high-pressure cold forging, each washer is shaped with accurate geometry and uniform grain flow, improving mechanical integrity and dimensional precision.
CNC Machining – The serrated contact surfaces are precisely machined and matched to guarantee perfect interlocking between the upper and lower washers.
Heat Treatment – Controlled quenching and tempering enhance hardness and resilience, ensuring stable locking performance even under vibration or repeated loading.
Surface Treatment – Protective coatings such as phosphating or Dacromet are applied to increase corrosion resistance and smooth assembly operation.
Inspection and Testing – Every washer pair is verified through torque, dimensional, and anti-loosening tests to confirm consistent quality and reliable performance.
Surface Treatment Options for Double Stack Self-Locking Washers
Surface treatment plays an important role in the durability, corrosion resistance, and assembly behavior of double stack self-locking washers. Appropriate surface coatings help maintain consistent locking performance while supporting smooth installation and long-term service.
Common surface treatment options include phosphating and Dacromet coatings, which are selected based on operating environment, corrosion exposure, and customer requirements. For OEM projects, surface treatment specifications can be adjusted to align with application conditions and relevant standards.
Advantages of Double Stack Self-Locking Washer
Weforging’s self-locking washers combine cold forging precision and CNC machining accuracy to deliver reliable fastening performance:
Effective anti-loosening performance under vibration and dynamic loads
Stable preload retention without adhesives or secondary locking components
High dimensional accuracy for consistent assembly fit
Enhanced corrosion resistance for harsh environments
Suitable for repeated installation and long service life
Applications of Double Stack Self-Locking Washer
Weforging’s Double Stack Self-Locking Washers are engineered for high-vibration and precision fastening environments where stability and safety are essential.
Automotive Industry – Used in engine assemblies, suspension systems, and brake components to maintain secure fastening under constant motion.
Heavy Machinery & Construction Equipment – Ensures reliable joint stability in excavators, loaders, and hydraulic systems subjected to repeated impact.
Wind Energy & Power Systems – Used in turbine hubs and generator mounts where anti-loosening performance is vital for safety and efficiency.
Marine & Offshore Engineering – Protects critical joints in pumps, gearboxes, and deck structures operating in corrosive seawater environments.
Industrial Equipment & Automation – Maintains precise tension in robotic arms, presses, and assembly lines that require continuous movement and accuracy.
Specifications & OEM Custom Options
Weforging supplies double stack self-locking washers based on customer drawings and application requirements.
Size Range: Customized according to bolt size and assembly design
Materials: Alloy steel, carbon steel, or specified grades
Surface Treatments: Phosphated, Dacromet, or customer-specified coatings
Standards: DIN, ISO, or drawing-based specifications
OEM / ODM: Supported for custom dimensions, performance targets, and batch production
Why Choose Weforging?
As a professional self-locking washer manufacturer, Weforging integrates forging, CNC machining, heat treatment, and inspection within one quality-controlled production system. Each washer set is verified through mechanical and dimensional testing to ensure stable locking performance.
With extensive experience serving global OEM customers in automotive, energy, and heavy equipment industries, Weforging delivers fastening components designed for reliability, consistency, and long-term service.
Contact
Looking for reliable anti-loosening fastening solutions? Partner with Weforging today and request a free quote. Our forged and CNC-machined components are trusted by global OEMs for their strength, precision, and long-term performance.
