KP-55 Flat Washer 520K29

This flat washer, part number 520K29, is a precision replacement component from KUPA designed for use in the KP-series professional nail-drill handpieces (such as the KP‑55 and KP-60). It sits in the internal assembly of the handpiece (often near the spindle/rotor or bearing mount) and serves to provide proper spacing, load distribution and alignment of rotating components. Over time, the original washer may wear, become deformed or thin, leading to increased vibration, misalignment or premature wear of adjacent parts. Replacing it with this washer helps maintain the handpiece’s precision, smoothness and longevity.

Features

• OEM-approved fit: Listed by KUPA as “KP Parts Flat Washer #520K29” for KP-55, KP-55A, KP-60, KP-60A models and compatible units such as the Medicool Pro Power 20K/35K handpieces.

• Dimensions: Inside diameter ~ 6.07 mm; outside diameter ~ 8.02 mm; thickness ~ 0.29 mm. 

• Material: High-speed metal washer (likely steel or similar alloy) suitable for high-RPM applications.

Installation Tips

• Confirm that the existing washer in your handpiece matches the spec (6.07 mm ID / 8.02 mm OD / 0.29 mm thick) or is referenced as 520K29.

• Handpiece variants may use different washers or spacers depending on version—always check your parts diagram/manual.
  

• Disconnect the handpiece from power and ensure it’s fully stopped.

• Disassemble the front housing/spindle or internal rotor section carefully to gain access to the washer.

• Observe the orientation and stacking of washers/spacers/dust seals before removal.

• Insert the new 520K29 washer, ensuring it is seated flat and flush with surrounding components.

• Re-assemble the unit, and run under no-load at low speed to check for smooth rotation, minimal noise and proper alignment.