HEICO-LOCK® RING LOCK WASHERS

1. Pre-assembled locking system

• HEICO-LOCK® ring lock washers are supplied pre-assembled and offer the user the clear benefit of always being in the correct locking position – particularly important if being installed and removed repeatedly

2. Polyamide-Ring

• The plastic ring on HEICO-LOCK® ring lock washers is made from polyamide (PA)
• Other materials can be used for specific applications on request

3. Difference in hardness: HHEICO > HMaterial

• The surface hardness of HEICO-LOCK® ring lock washers is greater than that of structural grade and high tensile bolts (8.8,10.9,12.9)
  • Steel (through-hardened) 485 ±25 HV0.3
  • Stainless steel (surface-hardened) > 520 HV0.05

4. Difference in angles: α > β

• The wedge angle (α) between the HEICO-LOCK® ring lock washers is greater than the pitch (β) of the bolt thread
• This angle means the expansion in thickness of the HEICO-LOCK® ring lock washers is greater than the possible longitudinal movement of the bolt along the thread

5. Difference in friction: μa > μi

• The wedge-shaped surfaces have a considerably lower friction coefficient μi than the toothed outside of the washers (friction coefficient μa)
• Loosening caused due to dynamic loads causes movement between the two washers in the region of the wedged surfaces

6. Difference in preload: Fdyn > Fstat

• An expansion in thickness of the HEICO-LOCK® ring lock washers as a result of loosening leads to an increase in the clamping force
• This causes an increase in the preload compared to when in a static state and thus causes the bolt to self-lock
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