Sargent 578-2 Mortise Lock Spindle Kit | For Legacy 8100 Series

The Sargent 578-2 is a genuine OEM replacement dimpled spindle kit engineered specifically for Sargent 8100 Series Mortise Locks. This kit is the definitive solution for locks manufactured prior to January 1, 1990. The spindle serves as the critical drive shaft, connecting the interior and exterior levers to the mortise body. If your handle spins freely or fails to retract the latch, a snapped or worn spindle is the most likely culprit.

Specialized Engineering for Legacy Hardware

• Pre-1990 Compatibility: Custom-tailored to the specific internal hub dimensions of vintage 8100 series mortise bodies, ensuring a perfect mechanical fit that modern universal spindles cannot provide.
  
• Dimpled Design: Features precision-engineered dimples that allow set screws to "seat" deeply, preventing the levers from loosening or pulling off the door over time.
• Standard Door Fit: Specifically sized for 1-3/4" thick doors, the most common standard for commercial and institutional entries.
  
• Institutional Grade Durability: Forged from high-strength alloy steel to resist the high-torque forces required for heavy-duty commercial latch retraction.
• Sargent OEM Quality: Using genuine parts ensures your legacy lockset maintains its original mechanical integrity and smooth operation.

Technical Specifications

• Model Number: 578-2
• Series Compatibility: Sargent 8100 Series Mortise Locks
• Manufacture Date Range: Pre-January 1, 1990
  
• Door Thickness: 1-3/4"
• Spindle Type: Dimpled / Divided
• Standard Code: UNSPSC 46171500

The Sargent 578-2 is an essential find for maintaining historical or older institutional buildings where the original 8100 series locks are still in service. Because these older spindles can become notched or brittle over decades of use, we recommend replacing the spindle whenever you notice "play" or wobbling in the door handle.

Installation Note: For a permanent, "wobble-free" installation, ensure that your lever set screws are tightened directly into the dimples of the 578-2 spindle. If the trim itself is loose on the door, it can cause the spindle to bind or wear prematurely. To ensure the lockset remains perfectly aligned, verify that the roses or escutcheon plates are securely clamped using high-strength thru bolts. This prevents the trim from shifting and protects the new spindle from unnecessary lateral stress.