DIN6797J inner (or internal) serrated tooth lock stop washers are a type of specialized locking washer designed to provide a secure fastening solution where the locking action is primarily from the inner diameter of the washer. Unlike outer tooth washers, their serrations are located on the inner circumference, biting into the shaft or screw threads, or into a smaller mating surface. These washers are engineered to prevent fasteners from loosening due to vibration, shock, or thermal cycling by creating a positive mechanical lock.

Definition

A DIN6797J inner internal serrated tooth lock stop washer features a series of teeth or serrations along its inner edge. These teeth are designed to engage with and embed into the shaft of a screw, a bolt thread, or a smaller diameter mating surface (such as the base of a counterbored hole) when compressed. This creates a strong frictional and mechanical interlock that resists counter-rotation and prevents the fastener from loosening under dynamic loads. The “stop washer” aspect emphasizes their role in providing a reliable, anti-loosening function.

Advantages

• Anti-Loosening Performance: Highly effective in preventing fasteners from backing out under severe vibration and shock, offering a more reliable lock than plain washers.
• Positive Mechanical Lock: The internal teeth create a strong mechanical bond, enhancing the security of the fastening joint.
• Space-Saving Design: Often preferred in applications where the outer diameter of the washer needs to be minimized or where the locking action needs to be confined closer to the fastener’s axis.
• Material Protection: By biting into the fastener or a less visible internal surface, they can protect the aesthetic appearance of the outer component surface.
• Electrical Connection: The biting action can help break through minor surface contaminants to improve electrical conductivity in certain assemblies.
• Reduced Risk of Snagging: Without external teeth, there’s less risk of the washer snagging on adjacent components or clothing, which can be important in tight spaces or specific mechanical designs.
• Standardized Dimensions: Conforms to DIN6797J standards, ensuring consistent dimensions and performance for reliable application.

Applications

• Electrical and Electronic Assemblies: Often used in sensitive equipment where external teeth might interfere or where a low-profile lock is needed.
• Small Motors and Appliances: Ideal for securing internal components where space is limited and vibration is a concern.
• Automotive and Aerospace: In applications requiring a compact and secure locking mechanism, especially for internal engine components or control systems.
• Machinery and Robotics: Used in precision machinery where specific component security against vibration is crucial, and external interference needs to be avoided.
• Gearboxes and Transmissions: Securing shafts or internal gears where rotational forces are high.
• Instrumentation: In delicate instruments where fine control over fastening and minimal external footprint are required.
• Any application where the outer diameter aesthetic or function of the assembly is critical: The internal teeth avoid marring or interfering with the outer surface area.