DIN 6798 Serrated lock washer internal teeth Form J
External tooth lock washers manufactured according to DIN 6798 allow the immobilization of fasteners such as bolts and screws which are subject to vibrations while maintaining uniform tightening torque in any mechanical electrical or electronic application. In addition to the anti-vibration characteristic, this washer also improves the quality of electrical circuits as each of the inner teeth forms an excellent point of contact. This washer is recommended for use in inaccessible application zones where it may be difficult to tighten the bolt or screw once fitted.
Form J is particularly recommended when the angle of the internal chamfer of the head of the bolt or screw is pronounced and in all cases where head is smaller than the diameter of the washer.
This washer should also be used when the surface of the fastener is irregular or convex.
The permanent inclination of the teeth, which are superimposed one upon the other around the circumference of the washer, gives a very high friction factor allowing for progressive and evenly distributed tightening torque around the head of the bolt or screw.
The tightening torque applied on the teeth of this washer should in no case exceed the recommended tightening torque for 8.8 class bolts.
When tightening torque is applied the edges of the teeth of this washer are incrusted in the head of the bolt or screw, forming an immobile unit resistant to loosening.
HV 350 ÷425 / HRC 36 ÷43