Full name:NF E25-511 French single-sided embossed conical disc shaped anti loosening washer, commonly known as French disc washer or single-sided toothed locking washer in the industry, according to French standards NF E25-511-1984AndDIN6908The structure is similar.

✅ structural principle

The gasket body is a conical disc，Single-sided radial knurled tooth pattern; During installationThe knurled teeth face the connected parts. After the bolts are tightened, the disc is flattened, continuously outputting disc-shaped elastic force, while the radial teeth on the surface mesh with the workpiece surface.The disc's elastic compensation preload force + Rolling flower bite anti slip Dual anti-loosening measures can resist bolt loosening under vibration and impact, providing a stronger anti-loosening effect than ordinary flat washers and spring washers.

✅ common materials & Heat treatment

1. 65MnSpring steelThe most mainstream, quenching and temperingHRC38~45，Good elasticity and adaptability 12.9/8.8/10.9High-strength bolts; Surface optionalGalvanizing, blackening, DacrometDacromet salt spray800h+)ruiqinstan...

2. SUS304 / SUS316L Stainless steel:A2-70,A4-80Corrosion-resistant, suitable for damp, outdoor and chemical environments, with a hardness slightly lower than that of manganese steel

✅ specification

Common thread specifications M3~M20，Divided into narrow and medium types Two series; Thickness0.5 to 3.2 mmThe standard inner diameter, outer diameter and cone height shall be implemented in accordance with the legal standards, and non-standard customization is supported.

✅ Core features

· Double anti-loosening: Disc-shaped continuous elasticity+Radial knurled interlocking anti-slip

· Small size, compact installation space, can be used alone, no need to stack multiple pieces

· The preload attenuation caused by the thermal expansion and contraction and creep of the compensable bolt

· NoteKnurled teeth will leave indentations on the surface of the workpiece. Use them with caution on soft substrates (aluminum, plastic)

✅ application scenarios

Automobile chassis, engines, construction machinery, motors, elevators, rail transit, power equipment, fans, etcContinuous vibration conditionThe bolt connection; It is mostly used for anti-loosening and locking of high-strength bolts to replace traditional spring washers.

✅ Installation points

1. The side with knurled teeth is in contact with the workpiece, and the smooth side faces the nutIt cannot be installed in reverse. If installed in reverse, the teeth will not be able to bite, and the anti-loosening function will fail

2. Matching with bolt grades65MnCompatible with the product8.8High-strength bolts of grade one and above

3. Not recommended for connections that are repeatedly disassembled, as they may experience rolling wear and reduced anti loosening performance after repeated disassembly