External tooth lock washer | A2 | DIN 6798
Do you need a lock washer that works reliably in both indoor and outdoor environments? External tooth lock washer A2 DIN 6798 AZ in stainless steel (A2 / AISI 304) is developed to provide reliable locking action and a long service life. The radially placed teeth grip into the substrate or the contact surface of the nut, creating effective friction that prevents the assembly from loosening due to vibrations and movement.
APPLICATION AREA
Perfect for fastenings where vibration protection is required in construction, machine engineering, industrial installations, and outdoor use. The toothed design makes the lock washer easy to install and provides a stable, self-locking connection without additional locking elements.
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TECHNICAL SPECIFICATIONS
Product type: External tooth lock washer
Standard: DIN 6798 AZ
Quality: A2 / AISI 304 (stainless steel)
Material grade: Not specified (stainless steel without strength class)
Thread type: Not applicable
Surface treatment: Untreated (natural stainless steel)
Head shape: Not applicable
Drive type: Not applicable
FREQUENTLY ASKED QUESTIONS (FAQ)
What is an external tooth lock washer (DIN 6798 Form AZ) and how does it work?
An external tooth lock washer (DIN 6798 Form AZ) is a spring-type locking washer for screw joints exposed to movement or low/moderate vibration:
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Toothed grip (Form AZ): The washer's external teeth are angled and placed along the outer circumference. When tightened, the teeth spring together and dig slightly into both the contact surface of the screw head/nut and the underlying material.
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Friction and spring force: The combination of the teeth's mechanical grip and the integrated spring tension prevents the screw or nut from loosening during minor vibrations.
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Electrical contact/grounding: By cutting through thin oxide layers, paint, or surface treatments, the teeth also create very good electrical contact, making the washer popular for grounding terminals and electronics assembly.
Why is stainless steel A2 (AISI 304) suitable for this lock washer?
A2 steel (1.4301 / AISI 304) provides an excellent balance between corrosion protection and mechanical spring capability:
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Withstands outdoor environments: Endures rain, snow, humidity, and damp indoor environments without suffering from rust or performance degradation (Corrosivity category C3).
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Retains tension: The stainless material maintains its spring properties over time without becoming brittle.
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In highly corrosive/marine environments: If the lock washer is to be submerged in salt water, exposed to road salt, or heavy chemicals, acid-proof steel A4 or wedge-locking washers (e.g., Nord-Lock) are recommended instead.
What should be considered when installing toothed A2 washers?
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Pair with stainless screws: Install the A2 lock washer together with stainless A2 or A4 screws and nuts to completely avoid galvanic corrosion.
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Surface sensitivity: Since the teeth grip into the substrate, small marks are made on the contact surface. Do not use toothed washers on delicate, softer surfaces where scratches are not permitted or where the corrosion protection (e.g., a thick paint coating) must not be breached.
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Used for moderate vibrations: For extremely heavy vibrations, dynamic impacts, or cyclic loads, mechanical wedge-locking washers or nyloc nuts are recommended, as toothed washers function best as spring-loaded friction locking in light to medium-duty assemblies.