Standard:DIN25201German standard wedge-shaped self-locking washer, commonly known as double layered self-locking washer in the industry，Use two pieces as a set

✅ structural principle

Each gasket:One side is the outer radial knurled teeth, and the other side is the inner wedge-shaped CAM inclined surface. ✅Installation rulesTwo wedge-shaped inclined surfaces are in close contact with each other, and the outer radial teeth respectively bite the workpiece and the end face of the nut；They are often pre glued together at the factory for easy assembly.

Core wedge self-locking principle: The wedge angle α on the inner side of the washer is greater than the bolt thread angle β. When vibration causes the nut to loosen and rotate，Only the internal inclined surfaces of the two washers are allowed to slide and lift relatively；The axial elongation caused by lifting is greater than the pre tightening amount reduced by thread loosening -The more vibration there is, the higher the preload of the bolt will be, achieving dynamic self-locking，It's not just about relying on friction to prevent loosening.

✅ material & Heat treatment

1. 65Mn / S60CSpring steel (mainstreamQuenching and tempering, hardnessHV≥450; Adaptation8.8,10.9,12.9High strength bolts; Surface treatment: Dacromet (zinc aluminum coating), blackening, galvanizing, Dacromet salt spray performance is optimal, wind power/Outdoor first choice

2. SUS304 / SUS316LStainless steel(A2/A4），Corrosion resistance, chemical and marine humid environment, low hardness, suitable for medium and low loads

3. Heavy duty high temperature optional50CrVAAlloy spring steel, etc

✅ range of specifications

Thread matching M3~M130; Regular spot goodsM6~M36It is commonly used in wind power and construction machineryM12/M16/M20/M24/M30.

✅ Core features

· Top-grade strong vibration anti-looseningJunker The vibration test performance is far superior to DIN6796,NFE25-511

· The anti loosening performance is not affected by lubrication and remains reliable even after oil coating

· DetachableReusable(As long as the tooth surface is not severely crushed

· ⚠ ️External radiating teeth may compress soft substrates (aluminum and plastic parts should be used with caution)

· ❗It is prohibited to stack additional flat pads or ordinary elastic padsIt will directly lead to the failure of anti-loosening measures

✅ application scenarios

Wind power towers, rail transit, high-speed rail, construction machinery, mining equipment, heavy truck chassis, oil equipment, Bridges, power equipment;Key bolt connections with alternating impact, continuous strong vibration and high safety gradeIt is the type with the highest anti-loosening grade among the three types of gaskets

✅ Installation points

1. The wedge-shaped inclined surfaces are in face-to-face contact, with the external teeth facing outward, respectively biting the workpiece and the nut，Direction cannot be reversed

2. A set consists of two pieces.Do not use as a single piece

3. Suggested matching bolts are 8.8 or higher grade high-strength bolts

4. Tighten to standard torque without over tightening