Star – Tooth Washers
The main purpose of toothed lock washers is to permit the flow of electric current between components coated by varnish, anti-corrosive agents or similar materials. The bent ends of the washers piercing the coating when such components are joined. For such applications, the effectiveness of toothed lock washers shall be verified in accordance with the relevant DIN VDE Standards.
These are also used for locking a device and reducing the vibration. They reduce loosening by preventing unscrewing rotation of the fastening device; locking washers are usually also spring washers.
Washers are available in a wide range such as spring washers, star washers, multi-tooth washers, disc spring washers, wave washers, taper washers, safety washers etc.
Star Washers Internal Product Code: D11 
These are locking washers that form part of the serrated or toothed type of washers. They feature serrations or teeth that extend radially inward to bite into the bearing surface.
Their effectiveness is more evident on soft substrates such as plastics or Aluminium although they do resist rotation better than plain washers on harder surfaces. As per DIN 6797J
Materials
– Spring Steel
– SS AISI 304
– SS AISI 316. Available on request.
Star Washers External Product Code: B4D12 
These are locking washers that form part of the serrated or toothed type of washers. They feature serrations or teeth that extend radially outward to bite into the bearing surface.
Their effectiveness is more evident on soft substrates such as plastics or Aluminium although they do resist rotation better than plain washers on harder surfaces. As per DIN 6797J
Materials
– Spring Steel
– SS AISI 304
– SS AISI 316. Available on request.
Multi Tooth Washers External Product Code: D13
Standard : DIN 6798A
Materials
– Spring Steel
– Stainless Steel AISI 304
– Stainless Steel AISI 316. Available on request.
Multi Tooth Washers Internal Product Code: D14 
The multi tooth lock washer works best with smaller screws heads. It is useful where a good grip is required but the teeth should not be visible as they affect the appearance of the product. The internal teeth grip the screw head and are useful in preventing a backward motion.
Standard : DIN 6798J
Materials
– Spring Steel
– Stainless Steel AISI 304
– Stainless Steel AISI 316. Available on request.